Just repaint your wheels. Best paint for your silver alloys is made by Wurth (Silver Wheel Paint) Also, clear coat them with Wurth Clear Laquer Paint. (Canned spray paint) This is GREAT spray paint with a very nice spray pattern. It is a real no-brainer for the diyer. I got the spray paint from one of the detailer web sites, I think it was either Autogeek or Top of the Line detail products web site. One can will easily do two wheels, maybe four. Do a search (there is a diy on a BMW site) on spray painting your curbed wheels and you will find plenty of info. Wurth makes a great product.