Using a clay bar will remove embedded surface contamination that still remains after a maintenance wash. Sometimes the contamination removed is not always visible on the paint to the naked eye. After using a clay bar on your paint, you will be left with a surface that is smooth as glass and properly prepped to polish or apply your layers of protection. Not only can you clay your vehicles paint, but glass, wheels, lights and more. A common misconception about using a clay bar is that it has an impact on removing swirls and scratches, it does not. If anything, using a clay bar can actually add minor imperfections in your paint so it's always best to follow up with a polish to remove any added micro-marring.