Audi a4 RS8 alloys

[olds_kool]

photo would help but sounds like corrosion, do marks look like little white worms?
most alloys are painted but polished/diamond cut are lacquer over bare metal, and if lacquer gets chipped corrosion turns white and spreads along underneath, not a lot you can do other than refurb except keep them as clean as possible
had a set of ats cups on a mk1 golf gti which had same problem so i decided to remove lacquer and hand polish them, took about 8 hours each, not something id recommend!!!!!

[docurley]

Dont you mean S8 or R8.