I know there have been several posts on polishing aluminum wheels, and don't want to rehash the entire thing, but I had two quick questions. I have a '90 K5 with factory aluminum wheels. They have 15 yrs. of road wear on them but are not in bad condition at all. I wanted to polish them and make them look new. Question: There is a thin plastic-like film over the aluminum. I assume this is a way to protect the wheels. 1) How do I remove this film? 2) After polishing the wheels what would I apply to the wheels to replace this coating? Thanks for your help.