I saw an advertizment for WheelWax. The stuff looked like it worked great. Check out www.wheelwax.com, and they have the usual speil how their product is the best. I was gonna pick some up, because they actually sell it at a retailer in colorado(colorado product?), but I spaced it out. One of these times i'll pick it up and give a testamonial about it.
my personally advice is to just clean them regular, nothing special, just keep them clean. it's unlikly you'll ever get it to shine then when it came off the factory floor, some chrome just don't bling.