Road Noise; Reducing the Model 3 road noise, primarily from tires and louder on rough highway asphalt

[Georgesb2]

Tesla Road noise; some apparent progress!

Note: I have a 2022 Tesla Model 3 Performance. Your car might have different factory build details and different places that resonate and different places that "leak" noise into the cabin.

I've been dealing with both wind and road noise. It's not as bad as some other vehicles but the wind noise can be quite annoying. And on certain road surfaces the road noise can be quite irritating as well. It can be quite loud on rough asphalt, especially at highway speeds. In this post I'm only working on the road noise. I've made other posts and lots of YouTube videos on wind noise reduction, and I've had quite a bit of success with that. But for road noise, here we go.

I applied Second Skin Damplifier Pro Mats to the rear trunk and especially around the wheel wells. I chose that brand because they are made in the USA, extremely high quality, don't smell, don't fall apart, don't melt, etc. Just good stuff. I focused upon the wheel wells and the trunk based largely upon what IloveCoffee had to say about his model Y noise. That sound deadening mat application that I did was intended to reduce mostly low-frequency vibrations and perhaps some mid range that may be set off on rough roads and may set off metal reverberations in the trunk. Large cavities are prone to be “echo chambers” and metals have vibrational resonant frequencies, so it makes sense to me to dampen that. I did not feel that such metals would be high frequency sources. I felt that the mid and higher frequency noises came in directly from other gaps such as in the doors. My application of the sound deadening mats to the trunk and wheel wells seemed to work in that it seemed to effectively dampen lower to low/mid frequencies of noise. I didn't notice much noise at all at the lower frequencies in my subjective post application test drives.

But the higher frequencies remaining seemed to be bouncing all around the cabin! And they got all of my attention now. My guess is that the lower parts of the doors were letting the tire noises in. Down near the rocker panels the tire noise must be quite loud. This is logical and somewhere I read that this is likely the case. I felt that since the Model 3 has seats and quite a bit of factory sound absorption materials in the trunk, it would be difficult for higher frequencies to be sourced from the trunk to get into the cabin.

First I did a “test”. After I was done working on trunk and wheel well dampening. I loosely placed moving blankets against the doors in the rear seats, especially at the bottom. This seemed to really make a difference. So off I went to reduce the sounds coming in through the doors.

Again, this road noise I'm working on is the roar or noise that the tires make on asphalt. It is much worse on older or rougher asphalt. I've seen long stretches of highway with this noisy surface. It is sometimes loud enough to be quite bothersome. Other times it's just annoying in the background. I'd like to improve all that.

I added a D shape rubber weather strip you can buy aftermarket. Try to get the very best. Try to buy from USA and try to ensure it has 3M adhesive. Many Chinese knock offs claim 3M but have horrible sticking power. They do not actually use 3M, they just label it so. Also, it doesn't have to be very large. Buy some smaller or moderately sized. If you get it really large, the doors won't close. Put this D shaped rubber weather stripping around the door edge, right near the outer most edge of the door. Apply these extra D shaped rubber weather stripping from the the window trim closet to the rear of the car, near the top of the door, around corners and through and along the bottom edge and stop when you meet the inner vertical door segment. There on the leading vertical edge you should use Z shape rubber, which I have only done to the driver's door so far. Only applying the D shape to both rear doors, I found a HUGE reduction in remaining higher frequency resonating cabin road noise.

Mind you, this is subjective as I don't have sensitive noise instrumentation. But wow, if I'm even close in my subjective evaluation, this is a huge return on investment.

Also worth noting. The experts strongly suggest that for road noise you must apply a heavy rubber spray on coating or add sound mats to the wheel wells. I tried that on another car, and for me it wasn't worth the mess and the very significant labor and time it took. So I figured I'd either never do it on my Tesla or save it for last.

Without doing anything to my wheel wells on my 22 Model 3, the other two things I did do, the D shape rubber and the sound deadening mats in the trunk / wheel well areas, seems I've made great progress.

Additionally, the experts say you must apply multiple layers to the metal skin inside. I did not. Again, I want to go one step at a time and test by driving and listening. I only applied a single layer of sound dampening stuck directly to the bare metal in the trunk and around the wheel wells. I did not add the suggested additional layer that supposed to work for airborne noises remaining there. I just felt that not much airborne, higher frequency noise is coming from the trunk in the model 3. For now testing seems to support my speculation.

I strongly suggest just doing two things. Once you get your wind noise under control. Then for road noise first add a D shaped rubber to the outer edge, inside the door, all around except for the leading edge vertical. Than, apply sound deadening mats on the wheel wells inside and everywhere else in the trunk (after removing the black plastic and factory mats) that seems to be noisy by testing with knuckle rapping on it.

I hope I am correct and hope this is helpful.

 

[RichardL]

Any chance you could post some pictures of the rubber strips to show the location?

Thanks

 

[Georgesb2]

Any chance you could post some pictures of the rubber strips to show the location?

Thanks

Here you go, pictures.
The rubber lining the outermost door edge is what I added.
Please note, that although I subjectively feel it reduced road noise. I doubt it can ever be truly eliminated.
I've read more about noise transmission from outside to inside. The most important factor is to seal as completely as possible against all air, wind intrusion first. This method does some of both. It cuts further on air intrusion and also blocks paths to the inside of the door skin and the inside of the door body inside a closed door.
As I stated in my post, I recommend first reducing all window air leaks, then move on to these concepts.

 

[Milan Djabirov]

That drain port though - I'd make a slice below it on the rubber band.

 

[Georgesb2]

That drain port though - I'd make a slice below it on the rubber band.

Yes
I tried to keep the rubber below the drain plugs.

 

[Milan Djabirov]

Also adding these rubber bands causes lots of dirt and dust to accumulate on the sill below the door. Not worth the probably .5 decibel (if any) difference you'd get. And say you want to sell the car, you have to remove it and it takes a while to clean up that goo. You maybe better off the pad the inside of the door panels - it will be well hidden and probably make the same difference. The 2022 model 3 is not that noisy. Worse than the model Y, but way better than a brand new Corolla in my experience. Get the quietest tires out there if it bothers you.

 

[Milan Djabirov]

Yes
I tried to keep the rubber below the drain plugs.

When it's below the port, when you close the door the water will accumulate against the rubber on the inside assuming the d rubber seals well against the sill edge. Probably not a concern in practice as it is likely not a very tight seal, but it will still cause a mess visually.

 

[Milan Djabirov]

To add another data point. I had a defect on the child seat anchors - a strip meant to protect the rear bench seat from rubbing against the metal was not looped properly over the passenger side anchor and I had to remove the rear bench (lower part) the back seat to fix it. Did not reinstall immediately and drove around for a few days without the bench. The amount of road noise and rear motor whine penetrating the cabin without the bench is shocking. I'd say the rear bench provides 80% of noise penetration supression. So you may want to experiment putting more barrier between the trunk and the rear seat but not as easy to disassemble and reach.

 

[Georgesb2]

To add another data point. I had a defect on the child seat anchors - a strip meant to protect the rear bench seat from rubbing against the metal was not looped properly over the passenger side anchor and I had to remove the rear bench (lower part) the back seat to fix it. Did not reinstall immediately and drove around for a few days without the bench. The amount of road noise and rear motor whine penetrating the cabin without the bench is shocking. I'd say the rear bench provides 80% of noise penetration supression. So you may want to experiment putting more barrier between the trunk and the rear seat but not as easy to disassemble and reach.

This is a good input. Thank you.
I will remove my rear bench lower, I've done it a few times before, and add sound dampening and sound absorption there. It should make some improvement.
When you drove around without the lower rear bench, did you have the rear upper seat backs in the upright and locked position?
I've already done a lot of noise suppression in the trunk. But I've done nothing in the floors of the cabin, including nothin done underneath any seats in the cabin.

 

[Georgesb2]

This is a good input. Thank you.
I will remove my rear bench lower, I've done it a few times before, and add sound dampening and sound absorption there. It should make some improvement.
When you drove around without the lower rear bench, did you have the rear upper seat backs in the upright and locked position?
I've already have done a lot of noise suppression in the trunk. But I've done nothing in the floors of the cabin, including nothing done underneath any seats in the cabin.

 

[Georgesb2]

Also adding these rubber bands causes lots of dirt and dust to accumulate on the sill below the door. Not worth the probably .5 decibel (if any) difference you'd get. And say you want to sell the car, you have to remove it and it takes a while to clean up that goo. You maybe better off the pad the inside of the door panels - it will be well hidden and probably make the same difference. The 2022 model 3 is not that noisy. Worse than the model Y, but way better than a brand new Corolla in my experience. Get the quietest tires out there if it bothers you.

I did quite a bit of research on this and the research continues. Thank you for your inputs. In my case, it's all already installed. I have no regrets. It has reduced the road noise and that was my goal, and that's why I share.

I do not want to change the OEM performance tires that came with my model, as that's quite a hefty investment and I love the looks and the performance I get. When the day comes for tire replacement from wear, I will carefully select tire for both performance and road noise. I've done that with other cars and trucks as well. Different tires can make a huge difference. So I do agree with you but won't be doing that anytime soon.

I will continue to look for additional improvements to add to the car including further noise reduction.

I think this one is beneficial but in a surprising manner, and that's why I shared it. Most other reports were attempts to reduce wind noise. I don't recall anyone talking about road noise except for one. That one stated that a lot of the road noise seemed to accumulate in the rocker panel area. He suggested dampening it and or doing what I did to block sound entry near the door bottom. The theory being that when the sound gets underneath the door via air currents, then the sound can pass into the cabin. So I blocked it.

I was reading on a Sound reduction professional web site. They stated that reducing all opportunities for outside air getting in is the number one thing to do. So with the rubber at the outside edge, it reduces the air infringement opportunity.

My subjective tests indicate to me that there was noticeable improvement. I'll take what improvements I can get, even if each change produces but small contributions. I have a number of additional changes planned. I'll be reporting on what works mostly, and what doesn't.

This rubber did work. Everyone reading has to keep in mind that just one change does not get 100% solution, but when put together with other strategies, the car can be and is a much more rewarding enjoyable quieter environment.

I have found on slower roads, it's incredibly quiet now that I added that rubber! But I'm not done, I want total noise reduction at higher speeds and on rougher roads. Thanks again for your help.

rubber bands causes lots of dirt and dust to accumulate on the sill below the door

I've seen a lot of videos and a lot of comments that indicated the opposite. What everyone said was adding weatherstripping to the outer edge of the doors, kept the area on the sill cleaner. They meant when you open the door and look at the opening, it used to get more dirty before adding the rubber.

If you mean it gets dirtier outside the doors, below the doors, on the rocker panels? Interesting, but not a concern. Also, I don't know if you intended to call them "rubber bands". They are designed to be used as door weather stripping. The ones I got work quite well. The installation looks very professional. The particular ones I bought are really high quality. They stick and hold very well, very easy to put on, etc.

And say you want to sell the car, you have to remove it and it takes a while to clean up that goo.

I don't see any reason to remove it ever. If I sell, it will not detract but may add perceived value in it being much quieter. But If I did for some reason wish to remove it, I have no problem facing cleanup. I work on cars all the time. Clean up of that nature isn't all that challenging. But since it looks neat and factory, I don't see why I would remove it.

Noise is a very subjective issue. For me I find noise very annoying. I've read that others have the same issues. Yet, others could care less and turn up the radio or leave the windows open. The road and wind noise really bothers me and my ears and my head. A small reduction in noise is a big deal for me. There may be a few others out there with the same issues and sensitivity and they may also be willing to work hard for small improvements.

I will follow up on noise reduction under the rear bench seat bottom.

Thanks again

 

[Georgesb2]

To add another data point. I had a defect on the child seat anchors - a strip meant to protect the rear bench seat from rubbing against the metal was not looped properly over the passenger side anchor and I had to remove the rear bench (lower part) the back seat to fix it. Did not reinstall immediately and drove around for a few days without the bench. The amount of road noise and rear motor whine penetrating the cabin without the bench is shocking. I'd say the rear bench provides 80% of noise penetration supression. So you may want to experiment putting more barrier between the trunk and the rear seat but not as easy to disassemble and reach.

Thanks again for that input.
Today I took the rear bench lower out of the car. I applied Second Skin Damplifier Pro to anything that vibrated when I rapped it, which was most everything. Clearly the factory knew as well that it would be a noise source, they added an acoustic absorber to the front of that shelf. But they didn't do anything to dampen the metal. Instead they are relying upon the bottom of the bench seat bottom, and it's foam to do everything. My worry is there's lots of thin metal there waiting to sing. Now that I've addressed that too, I just test drove the car. The car is quieter with the combination of the trunk & wheel well treatment, the under the rear bench seat treatment, and the added rubber weather stripping described herein. On my dirt and rock driveway the car is now whisper quiet! It used to be quite noisy and I'd hear all the little stones and such. Now I hear nothing. I'm making genuine progress! The remaining road noise on the roads and highway seems to come from almost entirely the front. (That wasn't true at all when I started the work. The noise came from "everywhere".) I'll ponder what do do about the remaining noise from the front, and if I think there's any good bang for the buck, so to speak. The Second Skin factory rep wants me to spray a rubber spray in the wheel wells from the outside. It might help some. But I already did that on another car brand with no noticeable effect. It's a lot of work and very messy, so I'm putting that off till the end. There's also some aftermarket felt stuff. I'll drive a while before I do anything more. Could be more difficult to get. But first I'll see if I can better close off the space in front of the front doors and look for other approaches. But I have a few other tricks up my sleeve to try. I've ordered some more materials to work with. Just a hunch that the roof glass is adding to the echo chamber effect. I'm going to try something. I'll report findings when I'm done.

Thanks again for inspiring me to work under the rear bench seat bottom.

 

[XPsionic]

I just test drove the car. The car is quieter with the combination of the trunk & wheel well treatment, the under the rear bench seat treatment, and the added rubber weather stripping described herein. On my dirt and rock driveway the car is now whisper quiet! It used to be quite noisy and I'd hear all the little stones and such. Now I hear nothing. I'm making genuine progress!

Nice, take some pictures too.

I found that in my car, a lot of suspension/bumpy road noise is coming from the reverberation and "drum" effect from the horizontal panel behind the rear seats/under the rear glass. When I tap and slap it, I can hear that whole panel vibrating. For smaller bumps the car sounds solid and quiet, for bigger bumps and potholes, the panel amplifies the noise quite a bit. I've been trying to stuff some foam in between the panel and the rear deck metal above the trunk, but I'm having a hard time reaching back far enough to quiet down the entire panel.

See if you could look into that part of the car and if your panel is as loose and drum like as mine.

 

[Georgesb2]

Nice, take some pictures too.

I found that in my car, a lot of suspension/bumpy road noise is coming from the reverberation and "drum" effect from the horizontal panel behind the rear seats/under the rear glass. When I tap and slap it, I can hear that whole panel vibrating. For smaller bumps the car sounds solid and quiet, for bigger bumps and potholes, the panel amplifies the noise quite a bit. I've been trying to stuff some foam in between the panel and the rear deck metal above the trunk, but I'm having a hard time reaching back far enough to quiet down the entire panel.

See if you could look into that part of the car and if your panel is as loose and drum like as mine.

I'll have a closer look at that panel.
When I was in the trunk, I looked over that panel. It is very soft, like a flimsy plastic. I figured they did that to transmit sound intentionally. The subwoofer and it's amplifier are in that trunk. They are located behind the right rear wheel well and part of the box is tucked into the void between the outer car skin and that right rear wheel well. I decided not to remove it because when I powered down the car from the screen, the amp was still powered. I figured I'd fight that battle another time.
I haven't noticed road noise kind of sound coming from that panel.
At this point with all the work I did I don't hear much at all coming from the back.
But with your suggestion, I'll have a closer look.
If I wanted to dampen it, I could apply the sound dampening mats to it. But I also don't want to interfere with the sound systems design. I'll look at it further and think it through more.

Thanks

 

[Milan Djabirov]

This is a good input. Thank you.
I will remove my rear bench lower, I've done it a few times before, and add sound dampening and sound absorption there. It should make some improvement.
When you drove around without the lower rear bench, did you have the rear upper seat backs in the upright and locked position?
I've already done a lot of noise suppression in the trunk. But I've done nothing in the floors of the cabin, including nothin done underneath any seats in the cabin.

Yes, seat backs were in place, just the bench was removed. The bench itself has a high density foam that absorbs lots of sound but that’s about all that stops the motor whine and wheel well roar from penetrating the rear. It’s a drastic difference- in a way fun as it feels like you’re driving a barebones sports car with the loud exhaust replaced by motor whine.

 

[Georgesb2]

Nice, take some pictures too.

I found that in my car, a lot of suspension/bumpy road noise is coming from the reverberation and "drum" effect from the horizontal panel behind the rear seats/under the rear glass. When I tap and slap it, I can hear that whole panel vibrating. For smaller bumps the car sounds solid and quiet, for bigger bumps and potholes, the panel amplifies the noise quite a bit. I've been trying to stuff some foam in between the panel and the rear deck metal above the trunk, but I'm having a hard time reaching back far enough to quiet down the entire panel.

See if you could look into that part of the car and if your panel is as loose and drum like as mine.

I found this YouTube video. I start the video right where he shows what he did for that horizontal section. I still haven't gone back in there to decide what / if I'll do more about that part. But this guy in the video applied sound dampening materials all the way entirely across all horizontal section.

 

[XPsionic]

I found this YouTube video. I start the video right where he shows what he did for that horizontal section. I still haven't gone back in there to decide what / if I'll do more about that part. But this guy in the video applied sound dampening materials all the way entirely across all horizontal section.

I see, the section I was referring to is ABOVE where he put the damping materials. The fabric/cardboard/plastic panel that's part of the interior of the car is what's creating noise in my car, so when I knock on it with my hand I can hear it vibrate/reverb a bit, and the same noise is heard when the car goes over sharp bumps or potholes. In mine that black panel have just enough flex and movement above the metal frame/panels of the top of the trunk section to create a drum like rattling noise.

The metal that he put damping materials on doesn't seem especially high in resonance to me when I knocked on them, but I'm sure it wouldn't hurt to add some mass to that area regardless.

 

[Georgesb2]

Update: 29 October, 2023
I dampened the driver's side rocker panel

How to remove the rocker panel plastic cover:

https://forum.fixyourtesla.com/node/219

I think I had read someplace, and can't recall where, that the “rocker panel” area may be a major source of tire noise getting into the cabin. It's certainly logical.

So, after sound dampening the trunk, wheel wells, frunk and installing sound blocking rubber weather stripping around the doors I went after that area. I conducted repeated test driving, listening to the road sounds. With that, we felt most of the remaining noise was coming mostly from the area down near the bottom of the doors, or the inside of the rocker panels. I also feel like there's noise coming generally from the front and some just bounces around the cabin, generally. That I'll have to address afterwards in the next steps.

But I'm convinced of making progress. When on "good" asphalt, the car is quite quiet. Additionally when I drive over my dirt and tiny stone driveway, a place I'm very familiar, it's much more quiet. Just indicators of progress. But on nasty asphalt, the tire noise is loud and some still gets inside the car. My ears and head is quite sensitive to this kind of noise, so I'll put the effort in to reduce it.

I decided to figure out this rocker panel area noise and what could possibly be done. It took way longer researching the rocker panel of the Model 3 than the time it took to actually remove it. You can't actually remove what I call the rocker panel as it's one continuous metal from the rear quarter that wraps around underneath the doors. I also cannot see any way to access inside of that metal. But Tesla added a thick, long plastic piece underneath that metal. When I tapped the metal, it sounded hollow and resonating. The plastic was worse, shook, and somewhat loose to boot. Note that Tesla eliminated two bolts that would have secured it well to the metal. They also eliminated the threaded holes. Darn, if I want to secure it further I'll have to tape it or some other methods.

I figured I had to remove what can be removed and try to dampen these two pieces. I found instructions on how to remove the plastic. It's very simple. That exposed the bottom of the metal. After extensive cleaning, I put sound-deadening materials in “patches” between the attachment points, the entire length of the metal. I also did the same inside the plastic. I put everything back together.

I haven't test driven and I did only one side so far. I'll have to update this post thread with findings but I'm sure it will add value towards the overall goal.

 

[Georgesb2]

Update 30 Oct 2023
More sound reduction progress!
I did finish both rocker panels. I removed them one at a time and added sound dampening sticky back pieces everywhere that I could that would not show to the outside.
(I've been using a quality material called damplifier pro by second skin. I don't have any relationship with that company. I just like that it's US made, no smell, ease of use, quick shipment, great support. I've done one other car with it already.)
This work on the rocker panels seems to have reduced noise quite a bit.
It's not difficult. I don't know of anyone else doing it but i think there is good return for the effort there if your goal is to reduce road noise, especially from tires on asphalt.
The second rocker panel went much faster than the first. It's a relatively quick and easy job compared to much of the other noise reduction work. The most difficult part is being on the ground much of the time.
I test drove the car after both rocker panels.
Now in total, I've done the entire trunk including all wheel wells that I could access, the entire frunk, both rocker panels, added rubber to the doors especially down low, and some wind and air gap reductions at the windows.
The car is generally quieter. So this is progress.
I notice that as I reduce noise from one source, the next loudest source becomes apparent. I prefer this approach rather than just doing everything everywhere and not really knowing what is working and what isn't working. Also that's a more expensive approach.
It seems that the bulk of the remaining road noise is coming from the "front end". This is actually really "good news" because when I began, most of the noise seemed to be coming from behind me and the sides. With it changing, I feel I'm continually making progress.
In spite of sound dampening the entire frunk area, through the frunk I could not stop or dampen noise that might be conducted from the front wheels through the structure and on into the firewall area or on into the car. For that I may have to remove a wheel and all the materials in the wheel wells.
But also interesting is that It actually sounded like the sound may be primarily coming through the windshield! I hope not, I don't have much in my bag of tricks to block that. I'd have to dampen sources instead. And kill airborne sound remaining in the cabin, read on.
Today I'm supposed to get delivery of sound deadening material. I've not used this before but the description and specifications for it's ability to dampen airborne noise is promising.
I chose to buy American and I should get delivery from Second Skin of their acoustic panels. These are typically used inside buildings to absorb airborne sounds. Since I'm using it inside and the high temp specs are very robust, I intend to apply it to the roof glass inside the car. Stay tuned.
The reason I'm doing this is the impression that sound is "bouncing" around inside the cabin. I want to dampen airborne noise and stop any reflection from the ceiling. The ceiling is a great opportunity for airborne sound reduction. Once the sound gets in, I want to kill as much as possible. Think of a restaurant or bar you might have gone to. The ones with flat ceilings and walls can be very very loud when people are in there. But the ones with sound absorbing materials and sound absorbing construction techniques can be pleasantly quiet. So even though they don't dampen the sources (people and activity) they can get the sound controlled quite well.

Also worth noting that Tesla put pieces of this type of material behind the carpet on the vertical metal short wall underneath the rear bench seat. I'm not sure if they were intending to do cabin airborne sound dampening with this approach or just trying to dampen sound emanating from below and behind. So my use of it in the car's cabin certainly isn't entirely novel.

Hope my story helps someone

Sincerely,
George

 

[Georgesb2]

Update 30 Oct 2023
More sound reduction progress!
I did finish both rocker panels. I removed them one at a time and added sound dampening sticky back pieces everywhere that I could that would not show to the outside.
(I've been using a quality material called damplifier pro by second skin. I don't have any relationship with that company. I just like that it's US made, no smell, ease of use, quick shipment, great support. I've done one other car with it already.)
This work on the rocker panels seems to have reduced noise quite a bit.
It's not difficult. I don't know of anyone else doing it but i think there is good return for the effort there if your goal is to reduce road noise, especially from tires on asphalt.
The second rocker panel went much faster than the first. It's a relatively quick and easy job compared to much of the other noise reduction work. The most difficult part is being on the ground much of the time.
I test drove the car after both rocker panels.
Now in total, I've done the entire trunk including all wheel wells that I could access, the entire frunk, both rocker panels, added rubber to the doors especially down low, and some wind and air gap reductions at the windows.
The car is generally quieter. So this is progress.
I notice that as I reduce noise from one source, the next loudest source becomes apparent. I prefer this approach rather than just doing everything everywhere and not really knowing what is working and what isn't working. Also that's a more expensive approach.
It seems that the bulk of the remaining road noise is coming from the "front end". This is actually really "good news" because when I began, most of the noise seemed to be coming from behind me and the sides. With it changing, I feel I'm continually making progress.
In spite of sound dampening the entire frunk area, through the frunk I could not stop or dampen noise that might be conducted from the front wheels through the structure and on into the firewall area or on into the car. For that I may have to remove a wheel and all the materials in the wheel wells.
But also interesting is that It actually sounded like the sound may be primarily coming through the windshield! I hope not, I don't have much in my bag of tricks to block that. I'd have to dampen sources instead. And kill airborne sound remaining in the cabin, read on.
Today I'm supposed to get delivery of sound deadening material. I've not used this before but the description and specifications for it's ability to dampen airborne noise is promising.
I chose to buy American and I should get delivery from Second Skin of their acoustic panels. These are typically used inside buildings to absorb airborne sounds. Since I'm using it inside and the high temp specs are very robust, I intend to apply it to the roof glass inside the car. Stay tuned.
The reason I'm doing this is the impression that sound is "bouncing" around inside the cabin. I want to dampen airborne noise and stop any reflection from the ceiling. The ceiling is a great opportunity for airborne sound reduction. Once the sound gets in, I want to kill as much as possible. Think of a restaurant or bar you might have gone to. The ones with flat ceilings and walls can be very very loud when people are in there. But the ones with sound absorbing materials and sound absorbing construction techniques can be pleasantly quiet. So even though they don't dampen the sources (people and activity) they can get the sound controlled quite well.

Also worth noting that Tesla put pieces of this type of material behind the carpet on the vertical metal short wall underneath the rear bench seat. I'm not sure if they were intending to do cabin airborne sound dampening with this approach or just trying to dampen sound emanating from below and behind. So my use of it in the car's cabin certainly isn't entirely novel.

Hope my story helps someone

Sincerely,
George

I installed one airborne sound absorbing felt mat, as pictured, to the glass ceiling above my head, by putting it between the aftermarket screen and the glass. I had to make custom clips.

The test drive I got a subjective but noticeable improvement. Much less annoying pulsating mood too high frequency tire road noise. And less overall sound.

This car is getting pleasant.

I plan to add more to the rear, larger glass on this model 3.