Not sure how to explain this to get the picture across. I have a 2007 extended cab silverado 1500 with about 60k on it. When going over any road conditions that are somewhat rough i.e. washboard packed snow or similar the truck sounds like a 1953 Dodge rattletrap. It sounds like maybe the doors don't shut tight enough with each other to totally seal things off. If I slightly open the door while driving the rattle is next to nil. Is there some way of tightening things up to eliminate this. The truck is an ltz with the leather interior so it tends to creak a bit till things warm up but the door thing drives me nuts. Any ideas? Thanks.