Originally Posted By: grampi
Most alloys these days come with some sort of a clearcoat on them. The factory alloys on my Corolla got so bad with road grime/brake dust that nothing would clean them. I tried many different cleaners with my high pressure sprayer, and while some of it comes off, it's impossible to get rid of it all. If your wheels are to this point, you may have to get some paint stripper to remove all of the old clearcoat, then re-clearcoat them.
I would not recoat them unless you want to do the same all over again and do not want a show quality shine.
You cannot get a show quality shine from coated aluminum, to win shows you need to polish often.
To the OP, rub some aluminum polish on it, if it turns your rag black then there is no clear in that area. Check other areas to verify though.