My New Model S by Soflauthor (First 24 Hours and then 1 week later...)

[W8MM]

WRT a radar detector—not sure whether it would work or not.

The "cutout" is just to the right of the rear view mirror support when viewed from inside the car. It is at the very top of the windshield, and as best I can tell is about 3" x 3" in size. It is not visible to the naked eye (or at least to my eye) from either inside or outside the car.

This creates a problem because I have two fixed devices that must transmit through the windshield, and there is only room for one of them (the device that opens the access gate for my community). The other, my SunPass, won't transmit. I have to hold it out the car window or open the sunroof—very kludgy. Not happy about this. TM should work with their glass vendor to correct the problem and at the same time remove the distortion at the bottom of the windshield.

Metallic-coated glazing essentially "shorts-out" radio signals trying to pass through it. Conduction is the enemy.

I think the glass vendor is conforming to Tesla's specification for solar-rejection glazing. There are two ways to do this: 1) Silver-based atomically-thin metal coatings and 2) A 3M non-metallic (possibly ceramic-based) integrated film that costs more. If Tesla insists the windshield must have solar-rejection properties, I am aware of only the two above solutions.

Back in Roadster 1.5 days, a choice was available for coated or virgin windshield glass and I chose the non-coated windshield on purpose to avoid all sorts of RF problems like directional cell-phone coverage, radar detector disablement, EZ-pass problems, etc.. Audi learned their lesson decades ago and suspended a "hot climate glazing" package that included coated window glass on all sides of the car. They had many complaints and even bought back a few cars because cell phone users and gated-community residents couldn't uses cars configured with the package. Bentley went through a similar evolution of their windshields over the past 10 years or so from the same trouble set.

I guess Tesla took so much "heat" [;-)] from Roadster owners complaining of poor A/C performance that they decided to go for solar-rejection over RF compatibility.

 

[strider]

This creates a problem because I have two fixed devices that must transmit through the windshield, and there is only room for one of them (the device that opens the access gate for my community). The other, my SunPass, won't transmit. I have to hold it out the car window or open the sunroof—very kludgy. Not happy about this. TM should work with their glass vendor to correct the problem and at the same time remove the distortion at the bottom of the windshield.

Couldn't you just stick the SunPass in the frunk?

- - - Updated - - -

Back in Roadster 1.5 days, a choice was available for coated or virgin windshield glass and I chose the non-coated windshield on purpose to avoid all sorts of RF problems like directional cell-phone coverage, radar detector disablement, EZ-pass problems, etc..

I have the SolarGuard windshield on my 2.5. My FasTrak toll transponder works just fine (I pull it out of the glove box and hold it to a random spot on the windshield when passing through the gate) and my cell phone works just fine too (it's an iPhone so has crap RF properties to being with). FM radio reception is terrible and also I can't get WiFi in my car (was sitting in my garage and had great coverage outside the car but nothing inside). So the coating certainly affects frequencies differently.

 

[stevezzzz]

WRT a radar detector—not sure whether it would work or not.

The "cutout" is just to the right of the rear view mirror support when viewed from inside the car. It is at the very top of the windshield, and as best I can tell is about 3" x 3" in size. It is not visible to the naked eye (or at least to my eye) from either inside or outside the car.

This creates a problem because I have two fixed devices that must transmit through the windshield, and there is only room for one of them (the device that opens the access gate for my community). The other, my SunPass, won't transmit. I have to hold it out the car window or open the sunroof—very kludgy. Not happy about this. TM should work with their glass vendor to correct the problem and at the same time remove the distortion at the bottom of the windshield.

I discovered that my ExpressToll sticker tag wasn't reading at all in the recommended location at the base of the windshield on the driver's side. My Sig S #187 has a painted area at the top of the windshield; most of it is the attachment pad for the rear-view mirror (see attached photos) but to the right of the mirror is a small area that the Tesla customer experience rep confirmed corresponds to the non-coated area where you can attach transponders, etc. ExpressToll has moved to passive tags (presumably RFID) the size of a couple of postage stamps, so there's plenty of room for my needs, but probably not for those with larger transponders or more than one device that needs to share the space.

In the photo taken from outside the car you can see the sensor for the automatic windshield wipers mounted in the mirror attachment foot.

 

[Doug_G]

Couldn't you just stick the SunPass in the frunk?

Somehow I think solid aluminum is more conductive than a metalized window. You'd have to find some position where there's just plastic in front of the unit.

 

[Babylonfive]

I hoped I could pull back the frunk carpet and attach my EasyPass to the inside of the plastic front nose cone.
Would that work?

 

[dsm363]

I hoped I could pull back the frunk carpet and attach my EasyPass to the inside of the plastic front nose cone.
Would that work?

They say it has to be right under the rearview mirror so not sure. It's not that visible there so not too bothered by it. I wish they could make something universal that automakers could build into the car instead of relying on stickers to place on the windshield.

 

[Babylonfive]

My understanding is that it is RF only, so doesn't need to be visible.

They say it has to be right under the rearview mirror so not sure. It's not that visible there so not too bothered by it. I wish they could make something universal that automakers could build into the car instead of relying on stickers to place on the windshield.

 

[Soflauthor]

I contacted our state SunPass folks, who happen to have pretty good customer service for a state agency. They tell me they offer an external unit that is used by folks with windshield transmission problems -- mountable on the bumper (??). I plan on stopping at a Sunpass office to see what it looks like and whether I can mount it in some unobtrusive location.

 

[gg_got_a_tesla]

Does EasyPass have a backup lookup system like the Bay Area's FasTrak system?

With FasTrak, you not only get transponders but, can also register license plate numbers on their web portal (bayareafastrak.org) - even without a transponder, if you go through a toll booth, there are cameras there that take pictures of your plates and they are automagically correlated with registered plates; the billing happens seamlessly then.

I may not use my transponder at all when using the Bay Area bridges in the Model S (once I put the plates on).

 

[sublimaze1]

I contacted our state SunPass folks, who happen to have pretty good customer service for a state agency. They tell me they offer an external unit that is used by folks with windshield transmission problems -- mountable on the bumper (??). I plan on stopping at a Sunpass office to see what it looks like and whether I can mount it in some unobtrusive location.

If it is anything like the ones in Texas, it is a black bar that is about eight inches long and 2/3 x 2/3 inches (essentially a rectangle) that mounts to your front plate. It looks similar to the backup camera aftermarket units, only thicker. They have to be installed by special dealers (torx screw with a spindle in the middle to prevent people from nicking yours) and they do look a bit hideous, but no more hideous than they need to be. I had one on my 2001 750iL and it was not a big deal.

 

[MikeK]

Does EasyPass have a backup lookup system like the Bay Area's FasTrak system?

With FasTrak, you not only get transponders but, can also register license plate numbers on their web portal (bayareafastrak.org) - even without a transponder, if you go through a toll booth, there are cameras there that take pictures of your plates and they are automagically correlated with registered plates; the billing happens seamlessly then.

I may not use my transponder at all when using the Bay Area bridges in the Model S (once I put the plates on).

When I rented a car in Texas not so long ago, it included toll road access, which was based entirely on a camera system like you describe, with no transponder at all.

Are you sure that it's supported to drive through the toll booth without the transponder, relying just on the plate? The web site says a missing transponder is treated as a violation. I guess they maybe have a process where they check the plates in case your transponder just didn't get a signal, but I would think that if you did this a lot they might get grumpy.

The site also mentions that some rental agencies have plate-based toll collection, but it says that a transponder is required for the new "express" (HOT) lanes, so if you think you might use HOT, it's probably a good idea to get the transponder to work.

By the way, the Model S I saw near my Sunnyvale office had a FasTrak transponder in the windshield right in the area stevezzzz describes.

 

[Babylonfive]

If it is anything like the ones in Texas, it is a black bar that is about eight inches long and 2/3 x 2/3 inches (essentially a rectangle) that mounts to your front plate. It looks similar to the backup camera aftermarket units, only thicker. They have to be installed by special dealers (torx screw with a spindle in the middle to prevent people from nicking yours) and they do look a bit hideous, but no more hideous than they need to be. I had one on my 2001 750iL and it was not a big deal.

I am gonna figure out the 'behind the nose cone' method.

 

[4sevens.com]

I am gonna figure out the 'behind the nose cone' method.

start by opening the frunk and check under the interior trim. if you can get it behind plastic body parts then it could work. avoid metal.

 

[kevincwelch]

Illinois has a license plate transponder that can be obtained. Currently, the I-PASS website has a list of vehicles that may require the license plate transponder. Tesla is not listed yet, of course. However, I will probably investigate this possibility when the time comes. Alternately, since I rarely require the device, I may just hold it up to the windshield as I approach.

 

[strider]

Somehow I think solid aluminum is more conductive than a metalized window. You'd have to find some position where there's just plastic in front of the unit.

Good point. I had done this on my Corvette but now remember it had a plastic nose Maybe as others have suggested it could be zip-tied in place behind the plastic nose cone.

 

[jkirkebo]

Have anyone tried to remove the plastic nose cone to see if it is possible to mount toll road transponders there ? I'd much rather have mine out of sight than on the windshield...

 

[Robert.Boston]

Have anyone tried to remove the plastic nose cone to see if it is possible to mount toll road transponders there ? I'd much rather have mine out of sight than on the windshield...

There's been some discussion of this question on other threads. Consensus seems to be that access behind the nosecone will be possible, but this hasn't been confirmed by any current owner.

 

[Soflauthor]

There's been some discussion of this question on other threads. Consensus seems to be that access behind the nosecone will be possible, but this hasn't been confirmed by any current owner.

Tesla service is supposed to stop at the house to correct a few minor problems (i.e., passenger door alignment, passenger airbag light says "off") over the next few days. When they do, I'll ask about ways to get at the back of the nosecone and report back then. I took a look myself, but I don't want to do any damage, so I'll await TM service's recommendation.

 

[Babylonfive]

Have anyone tried to remove the plastic nose cone to see if it is possible to mount toll road transponders there ? I'd much rather have mine out of sight than on the windshield...

I would bet that the access could be acheived through removal of some frunk covers. You would then see the cone from the inside and be able to mount transponders and radar detectors there. A clear nose cone (or portion) would even allow laser detectors, IR distance meters, etc.

I'd even like to see if a mobile cell amplifier could go there too...

 

[artsci]

I would bet that the access could be acheived through removal of some frunk covers. You would then see the cone from the inside and be able to mount transponders and radar detectors there. A clear nose cone (or portion) would even allow laser detectors, IR distance meters, etc.

I'd even like to see if a mobile cell amplifier could go there too...

I think you'll have to remove the bumper -- can't imagine you'll get access through the frunk but I could be wrong.