My 2005 G6 GT has has had a steering clunk that occurs when the wheel is quickly turned back after making a turn since it was new (car has 8K on it now). Occasionally I can feel the clunk under hard acceleration and can always feel it if I turn the steering wheel back and forth quickly. I had the dealer look at it last week during an oil change visit. The tech agreed there was an issue and the service writter said there is a factory notice on it. To make a long story short, the car will be going in for a new steering rack next week.