When I pulled into a parking spot in a parking lot, the car seemed to go faster than I intended. I swiped a car next to me, which to me as it was not a tight space. I immediately, turned off the engine and dealt with the passenger of the other vehicle, exchanging information. After sometime, I got back in my car to move it to another location. As soon as the motor was running in reverse, in began to accelerate making a loud roaring noise. I stepped on the brakes, meanwhile going in reverse at an accelerating speed, trying to keep away from cars parked on either side. I also pulled up the emergency brake. At the end of the row, I felt I could move forward without hitting many cars and hoping that in doing so, it would now slow down. It did not. At that point, I thought the only way to stop it, was going to be hitting something. (I did not want to go out of the parking lot into traffic). I aimed for a small tree, not realizing that there was a high curb surrounding it. The car hit the curb and flew over it, missing the tree, blowing out a rear tire, and hitting another parked car. That car slid into another car causing a chain reaction with still another car. There were 6 cars that were damaged in all. My insurance company is involved, but I do have a cap on how much liability I can pay.