The rules of Fireball Run are, on their face, pretty simple. Two people per team minimum, four maximum. The car that runs the rally must actually run the rally--no trailering or support vehicles. The main team registrant must be a business owner, worth over $3.5 million, a celebrity, an active or retired member of the U.S. military, or for 2010, a member or veteran of any law enforcement, emergency medical service, or fire department.
The drivers must have completed a basic defensive driving course, and the drivers that will compete on the track must have completed a racing school or have enough on-track experience to constitute a waiver. Drivers with any DUI/DWI on their record aren't allowed to compete or participate.
Beyond that, it's all about safety equipment and vehicles. But then there are the competition rules--the rules that govern the daily missions, driving, and track events. Those get a little more complicated.
We'll spare you an attempt to condense them and just send you to the official Fireball Run site to get the unfiltered ruleset if you really want to understand what it is we're up to.