Hi All. Just got new car with BMW Ceramic Coating and started using CP Reset from Foam Cannon and rinsing only with power washer, no mitt or sponge used. Result is greasy black film left on surface and nowhere near as squeaky clean as when it was delivered. Am I using too much shampoo or do I need to use a Mitt / Sponge in lieue of just rinsing off ?? Any comments much appreciated.