The Fremont factory Tesla acquired in 2010 was known as NUMMI.
NUMMI stands for New United Motor Manufacturing, Inc., a joint venture formed by General Motors and Toyota. The Fremont plant opened under GM in 1962, then reopened as NUMMI in 1984. Toyota brought its production methods to the site, making the factory a notable case study in industrial quality and workplace organization.
NUMMI ended production in April 2010 after GM's bankruptcy and Toyota's decision to withdraw. In May of that year, Tesla announced an agreement to buy most of the site from Toyota for $42 million. Tesla took possession in October and began converting the former joint-venture plant for electric-vehicle production.
The site is now generally called the Tesla Fremont Factory, so “NUMMI” refers to its former operating identity rather than its current Tesla name. The plant later produced the Model S, Model X, Model 3, and Model Y, linking Toyota-GM manufacturing history with Tesla's expansion into mass production.