Flickr user Steve Jurvetson (cropped from original, used under CC-BY)

Tesla is one of the largest employers in the Bay Area, with around 10,000 workers at its factory in South Fremont. That factory used to be the NUMMI plant, where General Motors partnered with Toyota to learn how to run an efficient assembly line with a relatively happy work force. Some current Tesla employees once worked at the NUMMI factory, which had a union. The Tesla factory does not.