I have taken my car to my dealer four times and the car still has a vibration, and the steering wheel intermittently shakes side-to-side at speeds of 45 and up. The problem is most noticeable at 60 and higher. The Quality Control guy said it had a problem but the service manager claims it is fine. I hate driving my new for more than 5 miles. I will not buy another new GM because of this problem and the attitude of the Chevy dealership.