Just leave them as-is, i work on a powdercoating line and yes rims do come out very clean, depending on which companies paint you use(dupont,tiger,ppg,ect.) i had a 93 camaro and a 97 firebird that i took the rims in and shot them up, and they came out great in black! only problem is, its black! any brake dust on them and it looks horrible, i had to clean those things every day! bigger hassel then its worth, aslo did them for a 05 325i beamer, those looked good!!! i still say dont do it, not worth the pain in the @$$! but if thats what u want make sure wherever you take them in that they have either a super strong sand blaster or a shotblaster, otherwise its almost impossible to get factory paint/ chrome back to bare metal, the best part about powdercoating rims is you will never ever ever have to worry about scratches or chips in paint again, our stuff comes with a 1,000,000 mile paint warrenty and it holds up!