Just recently my brother and I have discovered how to create a highly awesome contraption on Super Scribblenauts. Here are the instructions:
1. Spawn a supersonic car.
2. Spawn some glue, then attach it to the front wheel of the car.
3. Spawn a sword (or a zanbato. You can also make it deadly).
4. Position the sword so the point is facing in the same direction as the car, then attach the sword's hilt to the glue on the front wheel.
5. Hop in the car and drive in one direction. Enjoy!
The sword will spin with the wheel, going partway through the ground and causing the front of the car to rapidly move up and down. The car will still move forward, but will start to jump and flip rapidly (even more so if you are using a zanbato). Any NPCs nearby will be killed by the rapidly spinning sword, and the car will be able to traverse most terrain. But be wary of enemies, as even if the car is invincible, its wheels can still be destroyed, which will ruin this awesome contraption. This method also works with other wheeled vehicles (such as a battering ram).
Try it out!