While trying to back gently out of a parking space in a college parking lot after dropping off my son, my 2007 Toyota Matrix involuntarily accelerated and even though I was slamming on the brake, it continued to do so slamming into an oncoming car. When I tried to drive it forward out of the way of the car it accelerated again, jumped a parking barrier, jumped the sidewalk, raced up the lawn with me drastically trying to brake. I lost all steering as the back brakes locked but the front wheels kept traveling. The car sideswiped the side of a building, knocked off the rain spout that was hanging off the building. The only thing that stopped me was a tree root that the college was in the process of removing and two tree limbs that hadn't been trimmed yet. The car was still spinning it's front wheels as it was trapped on the root. I was trapped in the car and had to exit out of the back door. The car was declared totaled and I was almost relieved because I knew I would never get back into a Toyota again. I now own a very safe 2011 Nissan Versa.