I was working on my wifes car this weekend I noticed that my pad was not sitting flat on the panel when I had my pc on 5. It had a bowl look to it, and if I went to 6 well now way it just formed around the back plate. Is this caused by to much product build up and time to clean the pad and use a new one? I noticed when I was done with half the car. I probably answered my own question but I need to make sure lol. Thanks for the help..:dblthumb2: