A great trick to see your progress is to spray or wipe a coat of PPG wax and grease remover (DX330) onto the primer. The DX330 gives the primer a shine as if it had a clear coat on it letting you see if there are any waves in the bodywork. When finished, dry the excess DX330 with clean paper towels. With the whole side of the car sprayed with DX320, Jon Byers and Sean look for any imperfections in the bodywork. Rocking side to side while looking at the reflections in the wet DX330 the highs and lows really jump out. If there is any more work to be done it can either be sanded out or re-primed and re-sanded. Once again, dry the excess DX330 with clean paper towels when finished.