Having worked at the plant in Fremont: The design has probably changed multiple times just in the past month. They were constantly making small little changes to the way various things were put together so that not even a single batch of cars made in the same day would necessarily be exactly the same design. It was one of the few cool things about how they operate.

Safety of the workers in the plant worked the same way. Some dude biffed his forklift and almost took me out with his long-ass load. Managers and safety people were on the scene in less than 5 minutes and already laid out new rules for the forklifts about how long their loads could be to prevent it happening again.