I was already parked in a spot in a public parking lot. I tapped the accelerator pedal to move the car a few inches. The vehicle responded by violently accelerating, hitting a vehicle directly in front of me in another parking space. I applied my brake but the car would not stop. The force of the acceleration pushed the car out of the it's spot and it hit a curb and tree appox 30 ft away. In defensive move I turned my wheels to the right and continue to try and brake. This caused my car to hit the car on the right side of me. Property Damage occured. No injuries. Vehicle defect.