Since early 2004, Spirit has been autonomously driving around a 3 mile test track in San Diego, California. This allows the vehicle to become even more proficient at handling sensors in off-road conditions. Testing includes all sensor types used by this autonomous vehicle.

The vehicle has proven the capabilities to follow a GPS route, avoid obstacles, and determine the quickest path from one waypoint to the next. SD testing helps prepare for a successful DARPA Grand Challenge while the team gets answers for GPS multipath errors, road following, and .path planning. Barstow media demonstrations are scheduled to be held in the summer of 2005.