I have owned my car for 2.5 years and I have had to balance my tires over and over again. Each time I ask the dealership or tire store, they jsut shrug it off like nothing is wrong. Two weeks ago I got new tire (Pirelli's with 85,000 treadlife) thinking that tires could be the problem. Well, after a 1,200 mile trip the car started to vibrate again. I am wondering if it is a suspension or wheel problem. I know its not mechanical because each time I get my tires re-balanced, the car drives like a dream for a while......it is driving me CRAZY!