Vector-Z

I just powder coated my rear caliper brackets and polished the calipers. After reassembly and bleeding my brakes, I gave the car a wash and a wax. I used Mcguires wheel cleaner to clean my wheels and it seems to have tarnished the bracket coating. It also left "soap spots" on the polished caliper surface. I looks like my bracket coating is ruined! How do I clean the powder coated surface?