i was in a similar situation just recently when i bought a used M3 that had been car washed with acidic soaps for a good year. My clear over polished wheels were dull, and the wheel caps had yellow'd
i removed each wheel and polished them by hand with
Menzerna Final Polish (PO85RD). I spent a good hour on each wheel and this still didnt remove all scratches but made a very big improvement. I then cleaned them with Z-AIO, applied 3 layers Z5-Pro to minimise remaining swirls and then applied wheelwax to make washing/dust buildup more manageable. I also replaced all wheel caps with newbies
