Purchased our G6 in Dec. 2005 and had the brakes repaired twice under warranty. Now the front calipers are grabbing and causing rotors to overheat. Have a huge vibration problem on the exhaust when accelerating. Had the brake light come on and added brake fluid only to be told by mechanic I shouldn't have done that as it throws off the electronic sensor and they had to flush the hydraulic system out and put in measured amount of fluid to make sure it is accurate. For only 45,000 miles we have put a lot of money into service on this car. We are very disappointed with GM and will probably think twice about purchasing another GM product. They need to get their act together on quality.