in 1941 more than three million cars had been manufactured for the united states. only 139 more were made during the entire war. instead chrysler made fuselages, general motors made airplane engines, guns, trucks and tanks. and at its vast willow run plant in ipselanti michigan 67 acres of assembly lines under a single roof that one observer called the grand canyon of the mechanized world. the ford motor company performed something like a miracle 24 hours a day. the average ford car had some 15,000 parts, the b-24 liberator long range bomber had 1,550,000 parts. one came off the line at willow run every 63 minutes.