The 2004 Auto Club 500 was a NASCAR Nextel Cup Series stock car race held on May 2, 2004 at California Speedway in Fontana, California. Contested over 250 laps on the 2-mile (3.23 km) asphalt D-shaped oval, it was the tenth race of the 2004 NASCAR Nextel Cup Series season. Rookie Kasey Kahne of Evernham Motorsports won the pole, and Jeff Gordon of Hendrick Motorsports won the race.

Stewart–Haas Racing is an American professional stock car racing team that currently competes in the NASCAR Cup Series and the NASCAR Xfinity Series. The team is co-owned by three-time NASCAR Cup Series champion Tony Stewart and Haas Automation founder Gene Haas. It was founded in 2002 as Haas CNC Racing after Haas, whose company was a sponsor of Hendrick Motorsports, elected to form his own team. In 2009, Stewart, who had been driving for Joe Gibbs Racing, made a deal with Haas to drive for the team and in return receive a 50% stake in it.