i just bought a 2011 buick regal not even two months ago. Sometimes when I am driving, it will suddenly decrease in speed and the (D) drive indicator will flash. If i try to accelerate, it wont and the rpms will rev really high. Kind of like when you are in park and you accidently hit the accelerator? Also sometimes, but not always, when this happens the door locks will release. Whenever this happens I just wait a couple seconds and then try to accelerate again and it usually goes back to normal. no warning lights have displayed besides the flashing (D)rive indicator when this happens.