I have a black 93ls coupe and tinted it 15% metallic smoke llumar all the way around. They charged me $167 for the tint job. I'm happy with the tint, but the waterspots that were barely noticable before are really showing up. These acid rain waterspots won't wash off. I've tried 409,aerosol glass cleaner, windex, vinegar/water, razorblade, wax, etc. nothing works. What product have guys used that works?