A soap box car is a car you can build yourself to ride in. It's about half the size of a real car and doesn't have an engine. You just coast it down a hill.

You may be familiar with Pinewood Derby racing. You can just think of this as a pinewood derby car you can ride in.

The name "soap box cars" comes from the wooden soap boxes that kids used to use to build coaster cars. A race with soap box cars is called a soap box derby.

A fancy name I use for a soap box derby is "Gravity Gran Prix." A Gran Prix (pronounced Gran Pree) is a Formula 1 race. The Gravity Gran Prix uses only gravity to power the cars.

The national organization for soap box racing is the All-American Soap Box Derby. This is the official sanctioning body like the NBA is for basketball or the NFL for football.

Here's a good article on the All-American Soap Box Derby from Sports Illustrated.

Here's the Wikipedia entry on the All-American Soap Box Derby.

Here are 75 facts about the All-American Soap Box Derby.

Those articles are obviously for the official AASBD. There are many other non-official soap box derbies, like the Gravity Gran Prix that this site is about. The race we put on uses more open rules designed to make this fun activity available to everyone who wants to build a car or race.