So last summer the passenger side of my c-class didn't get it's usual polish. Even I was surprised at the tar and road film that built up on the paintwork. Super resin polish soon sorted that out though. Passenger side polished wing with passenger door showing 2 years of neglect. This is washed - all that yellow and black tar is stuck to the door. After half an hour of autoglym super resin, the original luster is just about back. Finish the door, apply some wax and it'll be stunning again.