The 2006 GFS Marketplace 400 was a NASCAR Nextel Cup Series stock car race held on August 20, 2006, at Michigan International Speedway in Brooklyn, Michigan.

Contested over 200 laps on a 2-mile (3.2 km) speedway, it was the 23rd race of the 2006 NASCAR Nextel Cup Series season.

Michigan International Speedway (MIS) is a two-mile (3.2 km) moderate-banked D-shaped speedway located off U.S. Highway 12 on more than 1,400 acres (5.7 km2)[1] approximately four-mile (6.4 km) south of the village of Brooklyn, in the scenic Irish Hills area of southeastern Michigan.

The track is owned by International Speedway Corporation (ISC).

Michigan International Speedway is recognized as one of motorsports' premier facilities because of its wide racing surface and high banking (by open-wheel standards; the 18-degree banking is modest by stock car standards).