I installed my xcarlink usb/mp3/card reader last weekend which had me disconnect the battery. I have noticed a monstrous difference in the way the car drives and shifts now.....wow the car actually feels smooth to me now. At first I thought maybe it was just me...but after a week now the car definitely seems to shift a lot better and the overall driveability is amazing! I guess I never thought to reset it when I bought the car.....maybe I should have. All I can say is wow....its a new car! I am so much happier with the driveability stock.