I have a question for any tire experts that may be out there. Is it possible to have a tire be completely balanced on a rim and still make the car shake at 55mph+? The guy at the tire place told me that the tire expands when it gets to those speeds and if the tire is cheaply made, it can lose it's shape and make the car vibrate. This seemed reasonable to me but I really know nothing about the subject. Anyone ever heard of such a thing?