Originally Posted by maxxm

Make that three. And I added an extra set of small rubber bumpers to make the contacts even better.

Another thing to check is the license plate and cover (if you use one). If you're using only the screws at the top and not those at the bottom (you might have to make two small holes for them), then the plate and cover can rattle and flap against the bumper section, particularly on choppy roads. That happened to me, too, but two screws at the bottom portion of the plate fixed it.