brake dust
#4
#7
i got a 2010 with factory 18 inch chrome rims, i use a cleaner called colonel brassy, it comes in a white plastic bottle and i got it at a napa store. it takes it right off no problems at all. i've sat and scrubbed those rims with everything i could think of but this is the only stuff that i got that actually works flawlessly and scrubs the brake dust right off!