Willow Run Assembly consisted of an assembly plant of 2.3 million square feet, another building that was known in later years as "Willow Run Company Vehicle Operations", covering 23,000 square feet on 22 acres of land, and perhaps other parcels.

[1] Production of automobiles began at Willow Run in 1959 with the Chevrolet Corvair; Willow Run also built the rear-wheel-drive General Motors (RWD) Chevrolet Nova (1962-1979), Pontiac Ventura, Pontiac Phoenix, Oldsmobile Omega, Buick Apollo, and Buick Skylark, the front-wheel-drive, the X-cars Oldsmobile Omega, and Buick Skylark (1980-1985), the front-wheel-drive H body Oldsmobile 88 and Pontiac Bonneville, and the B-body Chevrolet Caprice sedan and wagon, Oldsmobile Custom Cruiser wagon, and the Buick Roadmaster Estate wagon.

On May 14, 1969, the media was invited to Willow Run as the last Corvair came down the line; a departure from GM's policy of not permitting reporters to visit their manufacturing facilities.

Assembly operations at Willow Run ended in July 1993 after reduced demand for the full-size B-bodies.

[2] Willow Run Company Vehicle Operations became part of the abandoned GM properties managed by the RACER Trust in March 2011; in April 2013, RACER sold the Company Vehicle Operations facility to International Turbine Industries, an engine maintenance and repair company headquartered across Tyler Road from the former assembly plant.