[Darkmann]

During the winter, I often just dash into one of those coin-op car washes and give my car a blast as follows: presoak, brush on windshield only, high pressure soap, rinse, then I wipe down. I never blast directly on the sheetmetal, always at a very shallow angle. Most times I get all the dirt, except for the lower parts of the vehicle. Two questions: how hurtful is this practice to the paint 2) Is it true that these car washes use wax stripping detergents?