Vehicles must use original factory parts, and modern navigational aids like GPS are prohibited.
Points are awarded on the accuracy of a driver and navigator to match a time and average speed over a predetermined course.
Prizes are awarded in several categories, including the "X-Cup" for high school teams.
The slow speeds of the vehicles involved, combined with the long-distance nature of auto rallying have made television coverage of the event limited.
Although the name "Great American Race" has been applied to the Indy 500 and the Daytona 500, the events are not affiliated.