Originally Posted by Mike-in-Orange

If you use a quick detail spray as a lubricant for the clay then there is no need to rewash the car before moving onto the polishing/paint cleaning step. Some people like to use soapy water for lube and just go around and clay the whole car. In that case I would recommend a full wash before moving on. But since I don't like to make more work for myself, I always clay with a quick detail spray for lube.