I have a 2008 CTS with the 6-speed auto. and 3.6 DI and no AWD. I started the car to back out of the garage this morning and when I shifted into reverse and stepped on the gas the car wouldn't move. I tried to move it forward by putting it in drive, it still wouldn't move. Called Cadillac Roadside Assistance. He was finally able to move it. He said it appeard that the shifter interlock was binding which could mean a gear problem. I have to take the car to the dealership for further diagnosis. Has this happened to anyone else?:eek: