Those 400 are pre-production pilot cars to use as test mules, crash test cars, assembly quality control and process evaluation, etc.etc.etc.... They will all be destroyed when Ford's finished using them internally. Regular production will begin in September. This is the process for ANY kind of manufacturing. You build a bunch of testers, for testing, and for practice, before you flip the "go" switch and start building product for public consumption. There's so many wrinkles to iron out in the assembly process you cannot imagine, and the only way to discover them is to build practice cars.