I've tried to search for this and come up empty. I just put on a undercover SE tonneau cover. Every time I hit a bump I hear a rattle near the cab and its very annoying. It's almost like the cover is bouncing on the bed. My dads tundra with the under cover classic doesn't do this but it's 3 years old. I notice if I lift on the cover near the cab it pulls up half a inch or so. My Dads classic does not move at all. Any else hear anything about these covers rattling?