2009 Cadillac Cts has serious vibration at highway speed, after several attempts to resolve, changing the left front and the right rear tire, the dealer claims the car operates as designed, I see other complaints on Consumer Affairs website of the exact same issue. I have asked the service manager of the dealer to ride with me in the car. He failed to do so, and didn't show up for two appointments at his dealership to drive the car. The vibration was present when I test drove the car the owner of the dealerships son told me the vibration existed in many cars because of the tires getting flat spots. He assured me it would go away in 200 miles or so. 10,000 miles later the vibration still present. Since the vibration is worst between 64 or 75 miles an hour, and causes the steering wheel to shank the potential for a serious accident exist anytime the cars are driven on the highway.

- Warrenton , VA, USA

Heavy vibration and low pitch hum at approx. 45mph.

- Lancaster, NY, USA

2009 Cadillac Cts 3.6 direct inject engine. Starting at 700 miles vehicle started shuddering between 40-75 M.P.H. per GM they are aware of the design flaw but there is currently no fix for this engineering issue.

- Tequesta, FL, USA

Vibration in drive between 45mph and 60mph.

- New Hartford, NY, USA

Vibration in drivetrain at speeds between 45 and 55 mph.

- Dover Plains, NY, USA