The 2003 Sirius 400 was the 15th stock car race of the 2003 NASCAR Winston Cup Series season and the 35th iteration of the event. The race was held on Sunday, June 15, 2003, before a crowd of 160,000 in Brooklyn, Michigan, at Michigan International Speedway, a two-mile (3.2 km) moderate-banked D-shaped speedway. The race took the scheduled 200 laps to complete. At race's end, Kurt Busch of Roush Racing would make adjustments at the end of the race to pass Hendrick Motorsports driver Jeff Gordon on lap 177, and hold off Bobby Labonte of Joe Gibbs Racing to win his seventh career NASCAR Winston Cup Series win and his third of the season. Labonte and Gordon would fill out the podium, finishing second and third, respectively.