A great product on the market for sealing them was Zoops Seal, I think it's no longer made but has been replaced by a similar product called ShineSeal. It's kinda pricey though. Go search the name at Summit and look at the different kits they have, but you'll be out about $70 for the mini kit. Pricey.
Dunno man. I haven't sealed my Centerlines ever, but being rotary forged they have a really tight "grain" to the aluminum and hold a shine forever.
Some people wax their aluminum, seems to help. If you're in a dry area, raw polished aluminum will look good for a long time with very little care. Also many polished wheels do have a clear coat on them from the factory.
#1 thing though is get rid of your semimetallic brake pads if you're running them, and go high quality ceramic; I'd suggest Wagner Thermoquiet ceramic. All arguments about semimet vs. ceramic aside, if you don't want your wheels dusted to crap (that stuff eats the finish, too) and still want good braking power, go Thermoquiet ceramic.
Richard
