Probably road tar. 3M Adhesive Cleaner (08984) will dissolve it. I use cotton balls to apply it. Be careful about rubbing, or you'll scratch the clearcoat with the grit in the road tar. Let the adhesive cleaner do the work.
Originally Posted by mike in texas
Today I finished detailing my wheels and while doing so I was able to remove all of the black brake dust. Only problem I has is that some of the wheel look like ot had black gritty specks which I could not get off. Does anyone have any advice?
2002 M roadster