During my testing yesterday the pizza pans made a racket, I though they might be coming off, nope still on tight. It took me a few min to figure out what was causing the noise. If I push in on the center of the pans they flex in about 1/8" this makes the edges lift off the outer edge of the rim. when they come back they make a popping sound (try this at home, take a pan hold the edges and push in at the middle, release and that is that I have).
to fix this I was thinking of some felt pads on the inside of the pan, but they would not handle the wet weather very well. After some wondering around the workshop I got an inspired idea. I took some plastic tubing, slit it down one side and put it over the outer edge of the pizza pan:
I used some hot glue at the joint. Once on the car the bolts hold it tight to the rim!
After a test drive that pizza pan stopped making noise (I can hear the others still). Now I need to make a run to the hardware store for some more tubing (4.5" per pizza pan).