I recently started using clay towels for cars and now I want to share my experience, which is quite successful. Using a clay bar mitt involves lubricating the surface of your car's paint with a detailing spray or lubricant, then rubbing the mitt over the surface of the paint in a back-and-forth motion. This helps lift the contaminants from the surface of the paint and embed them in the clay, leaving your car's paint looking clean and smooth.