As my husband was backing out of the garage to the East and turning the back end to the North so we could head forward out of our drive which is on a curve, the car accelerated and the brakes would not work. We went backwards down a very steep drive that goes to our machine shed and towards the bottom we were stopped by a tree. We could have suffered head trauma from the abrupt stop. If we had been backing out of the drive or a parking place, since we couldnât stop, there could have been others involved and severe injuries. I called the sheriffâs office and they filed a report. Our insurance agent came out and took pictures. I called General Motors Buick and they opened a case. The car was towed to the body shop the dealership we bought it from uses. We noticed no warning lights or messages on the dash. After everyone left, I got on my computer and there were 2 diagnostic warning emails. One for the antilock brakes and the other for the StabiliTrac control systems,.