Having found a car with 3 wheels on it, we added a 4th wheel. The car started to float in the air (about 6inches off the ground). Whilst floating the car's wheels and steering wheel were rapidly moving back and forth.

We removed the wheels (because this use to fix the problem before), the wheel hubs and steering wheel continued to move back and forth.

I jumped into the driver seat of the car, and the car immediately jumped into the air, killing me. It continued to jump higher and higher after hitting the ground each time.