If your family is the kind that goes do demolition derbies, that is.
http://www.robotduck.com/dev/wrecker/index.htm
Use the arrow keys to control the weight. There are more cars as you advance in levels, and your weight also changes. You end with a 1 ton spiked stone.
:hint: hit more than one car in the same blow and you get a point multiplier for that blow.
:hint: you can also damage them just by staying in their way as they come.