INTRODUCTION
I love my new Model 3 Performance and want it to last. Having seen reports with scary pictures of rust-damaged Model 3s here on TMC (e.g.
Figure 1) and elsewhere, I began this thread to help make decisions on how to best protect it. Getting answers took some time. This post includes findings and solutions that hopefully will also help others. Sources include Tesla*, TMC in this and other threads, other forums, Google searches, You Tube videos, and even consultation with a Non-Tesla Tesla garage. Thanks to all who contributed and apologies if I forgot to give credit.
* The Service Center nicely fixed most fit and finish issues, and finally answered most of my questions – see post#1
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Figure 1. From Juanpelota in post#10. Other similar caseshave also been reported.
RUST DIRECTION
Tesla applies an electro coating to all conductive surfaces before any painting. There are hints that steel is also galvanized:
1. Car & Driver:
Tesla Model 3 Features and Specs
2. Comment in a post from 2 years ago:
“It´s galvanzides steel reg m3 specification! As most cars have today. Verzinkter Stahl rostet nur nach Beschädigung der Oberfläche.”
3. Tesla Roadside Assistance agent said that lower body steel parts are galvanized.
4. Some gray layers that look like galvanizing are showing in pictures like
Figure 1.
Rust from the inside seems unlikely given the electro coating and galvanizing that Tesla applies, with confidence to include a long warranty. I ran across no pictures of rust-through from the inside of Model 3s. It usually takes years to show up, but is covered by Tesla’s 12-year warranty, provided you don’t add any rustproofing. Thus, for now, I am no longer concerned about rust from the inside.
Tesla has included some additional protective measures to avoid rust from the outside-in. There are plastic covers and a chip guard under the paint, along the bottom edges of the rockers, that extends up to about 1” from the door.
But rust from the outside-in is
not covered by warranty and the model 3 seems to be vulnerable, as can be seen in
Figure 1. and others like it, usually from Northern climates where sand and salt are used in winter. The wheels pick up this abrasive, corrosive mess from winter-treated roads and direct it at the lower body parts, particularly behind the front wheels as shown in
Figure 1. In a short time, all of the protective measures, including the chip guard, are worn away, letting rust run rampant.
MYSTERY HOLE
The front plastic wheel well liners have a D-shaped opening where the fenders meet the rocker panels—see photo of left side in post#1. Through it, steel with only primer can be seen. Right in the path of sandblasting from the front tires, this looks like rust just waiting to happen! In post#4, Msjulie included the following interesting and relevant link:
FWIW
PSA front fender liners collect garbage
NO ONE KNOWS FOR SURE THE PURPOSE OF THIS “MYSTERY HOLE” Some theories:
· A means to collect garbage
· A way to rinse out collected crud
· A way to allow for big assembly tolerances
· A vent
· An aerodynamic aid
· A way to get at fasteners inside (but there aren’t any)
· An assembly feature no longer used
· “strategically located to collect all the road crap that gets kicked up by the front wheels”
· “to act as a time capsule to collect samples of all the roads you've driven”
· “I think they're holes to enable easy removal of the lining - big enough to get a finger it to prise it open”
The last 3 of these come from an entire TMC thread on this subject:
https://teslamotorsclub.com/tmc/threads/holes-in-wheel-wells.169632/ - post-4100157
It concludes that mud flaps to cover the hole are the solution.
This was one item on my list of problems that led to a visit to a local Tesla Service Center. They covered these holes with black Gorilla Tape, which others have recommended and I was going to do anyhow.
I have never seen such a hole in any other car, including the Model S loaner. Msjulie, in post#4, astutely asked “Anyone checked to see how the Y is built there?” I tried to find one to look at and even posted in a Model Y forum, with no luck. So I took some screenshots during a few Model Y videos, as shown in
Figure 2. Very recently, Tesla also told me that Model Y has no hole.
View attachment 553460
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Figure 2. Model Y has no Mystery Hole and much better protection of wheel arches and rocker panels.
It appears that Tesla learned from Model 3 how to make Model Y more robust. Perhaps there will be aftermarket or Tesla kits to improve the Model 3. The Tesla Model 3 winter kit has just become available again, see:
Model 3 All Weather Protection Kit
It includes only front mud flaps in 2 different sizes ($50). But these mud flaps only cover half of the hole! Installation requires you to cut off a plastic door underneath to access a fastener. They also offer rear dog leg PPF (Paint Protective Film- $50).
SOLUTIONS
Based upon what I have learned and recommendations of N54TT (post#2), XLR82XS (post#3) and others in other threads, I had the front end and all forward facing surfaces, the rockers, the doglegs, and the rear portion of the rear wheel arches PPF’d with clear, self-healing film. That was done by a local detailer Protection Plus in Shrewsbury, MA. Dave did a great job in less than a day and it has a 10-year warranty. He said mine had a decent paint job, except for lots of nibs.
I then installed mud flaps that protect the rear portion of all 4 wheel arches as well as cover the mystery hole (see
Figures 3 and 4). I used Evannex flaps, but others have recommended similar ones in this and other threads. As suggested by N54TT, I sanded any sharp edges that would be contacting the PPF. These flaps have a clip that grabs the fender lip up high. I added another layer of 3M PPF there, just to increase protection against scratching the paint. There were small holes in the upper portions of the flaps, which I covered with black gorilla tape. Then I applied 2 coats of Turtle Wax ceramic coating over everything, including PPF and windows.
View attachment 553462
Figure 3. Left Front Evannex Mud Flap
View attachment 553463
Figure 4. Left Rear Evannex Mud Flap. Rear bumper is plastic, so won’t rust, but sandblasting still takes off paint and looks ugly.
OTHER RELEVANT TMC THREADS
Home delivered, surface rust, rocker damage Home delivered, surface rust, rocker damage
Model 3 paint wearing off Model 3 paint wearing off
OTHER RUST ISSUES
Perhaps the earliest Model 3 rust issue was due to a front fender upper rear corner rubbing against the cowling, both steel. The following you tube video from Tech Forum (Northern Illinois) explains it well:
Good news is that Tesla will cover it. You can easily check the clearance by inserting a couple of credit cards in there. Mine is fine.
BTW, in a later YouTube video at 75K miles for the same white Model 3, Tech Forum reveled a problem exactly like
Figure 1.
There have also been reports of crud collecting in the plastic rear panel below the rear bumper.
MAINTENANCE
If you have an older Model 3 that was not protected with any of the measures listed above, keep an eye on the vulnerable areas mentioned above: the rear portions of the wheel wells, the rockers, inside the mystery hole (you may want to remove the lower portion of the liner as in :
PSA front fender liners collect garbage), the upper rear corner of the front fender, especially the left. Also, look above the plastic rear panel and remove anything that may have accumulated there. Depending on what you find, corrective measures may be needed. Begin with Tesla, since some of the issues may be covered under warranty.
If you have taken the suggested measures to avoid rust, it is still a good idea to, perhaps in the spring, remove the front mud flaps and taped-over mystery hole, then look at the vulnerable areas. You may want to remove the lower portion of the liner as in:
PSA front fender liners collect garbage). Hopefully there will be no rust and you can just flush out the crud and re-tape, then reinstall the mud flaps. Also, look above the plastic rear panel and remove anything that may have accumulated there.
Please post if you know of other vulnerable areas or have any questions or comments. Good luck.
I have a set of mud flaps from Evanex that should cover this hole, but they inexplicably have an open slot that lines up with it! Any comments or solutions will be much appreciated.
