It’s probably better to buy unused assembly plants like they did with Fremont. The costs must be enormous though retooling and such.
Is Elon building any assembly capacity at all?
Fremont (GM, NUMMI) - bought in 2010, 1st car 2012. Model S,S,3,Y, SEMI (2021), will build Roadster 2
Reno - currently batteries and future car mfg
Buffalo - solar products and Superchargers
Shanghai - broke ground 2019, Model 3 started Jan 2020, Model Y deliveries just started. For China and Asia market. 500K deliveries are expected in 2021.
Currently being built:
Berlin - Model 3 and Y, operations start mid 2021 - European market
Austin - operations late 2021 - Model 3 and Y for Eastern US, Cybertruck. This will be the biggest auto plant ever built
Future: Central US, Asia (South Korea or 2nd China), U.K. (rumor only)
Interestingly, I have owned 3 cars built at the Fremont, CA plant. 1965 4-4-2, 1993 Toyota 4WD PU, 2018 Tesla Model 3.