Check the rims if they have a clearcoat sprayed on them, if they have you will have to take it off and start polishing like a crazy. You can take the clearcoat off very fast and easy with a drill and a sandpaper flap that you can attatch to the drill but you have to be very carefull not to destroy your rims I'm telling you now it is a lot of work so if you have so money to spare you can better order some new rims or paint the ones you have. I know it sucks but that's how it works. If you buy new rims I would suggest the c-series sport Black rims so if you ever have problems just use a spray paint to touch up the rims. If you still want to polish them I wish you a lot of luck but it is a pain in the @$$ job.
