I did some looking around under my hood and couldn't come up with anything, do we know where the cosmoline is coming from? Before I take any serious steps to remove it, I'd like to know that I have stopped any future occurrence.
I’m thinking a Tornador with APC could get rid of the stains. If you know someone with any Tornador model, or a local mobile detailer with one, it’d be worth a shot. Or if you’re willing to drive up to a drab suburb in French Canada lol…
The TSB is posted elsewhere, but basically they heat up the part where excess Cosmoline lives (usually the hood, after it’s removed), drain out all they can, clean out the cavity and allow it to dry, then reapply the correct amount.
FWIW I had the same issue on my Signature base 2023 SE, brought it up to the dealer when in for warranty service today (defective side-scuttle), and they're ordering me new wheel arches from Germany as of today, 11/29/2022.
If you have OEM mud flaps make sure they order those as well. The originals are stuck to the flares with adhesive and need to be changed at the same time. I had to go back twice because they originally did not order the mud flaps.
FWIW, yesterday while washing I found Cosmoline seeping out around the washer nozzle housings. I guess I should be thankful that it’s way up in that area.
Would using rain-X help on the wheel arches? Sure, they aren't glass. But the folks over on the Solterra forum are saying that Rain-X would really help on the Solterra's rear window, which lacks a wiper ...
Does the dealership cover this for free? I have a 2022 I bought in March and tried to remove the cosmoline and now it looks faded. Did you guys make an appointment to get new front fenders?