Can't get rims clean

[Denalio]

You can try PS21 it is expensive, but non-corrosive. Spray it on out of the sun, agitate with a brush and let it fester overnight. Spray off with a garden hose. Acid wheel cleaner will etch the clearcoat if they are too strong. Use acid cleaner with caution. Check here for more ideas Removing caked on brake dust/grime - Thoughts? - Detailing Bliss Forum

[dhagopian]

Sort of a different problem from the original post but seems relevant here. My X3 has some fine scratches in the clearcoat on the wheels. Similar I guess to paint swirls. Would a scratch remover like Meguiars which is intended for paint work to buff them out?

[detailersdomain]

a good polish would work provided like you mentioned it has a clear coat.