I had proper baked on brake dust on my Image split rims after coming back from the Nurburgring last year and I bought some Rimwax after seeing it advertised in Evo mag and its brilliant stuff, think I paid about £14 for a tub of it. I expect its something similar to Autosol but I picked the Rimwax because it said that it would protect the rim for ages before needing doing again which it has, altho its due another light going over now after the last trackday.