p90d tire dust buildup

[jerjozwik]

so, a while ago i saw some black buildup on the rear bumper, just above the diffuser on the right side, thought it might be some important fluid depositing on the car. so gave it a clean to monitor the situation.

nothing ever showed up in that spot again but fast forward a few weeks and i see the wheel wells on both sides have accumulated dust build ups from the tires. now unfortunately i dont know if this is due to hitting the go peddle like it was meant to be hit or the result of tire camber. anyway i was curious if any p85/p85d/p85dl/p90d/p90dl/p100d owners are seeing anything similar?

 

[mahroni]

i have it too. i think it the tire dressing from the car wash that kicks up and ends up in that spot.

 

[Tessy Flyer]

I have been wondering what this was. Does anyone have an idea? It does appear it may be brake dust, but not sure as it seems a little greasy film to it. This is on all four wheels. I do use the dynamic braking, so the actual brakes are not used much. Is it possible it is something that happens when it is new and wears off an initial coating on the brakes or something. The car has less than 2,000 miles. Any ideas are appreciated.