If you're a small company (500 people for Tesla, apparently), building a never-been-built product and probably encountering lots of kinks along the way, it's probably worth having the factory be local.  The high-priced engineers who design the thing can just blast over to the factory while they're figuring out production issues.<p>Just speculating, of course.  But I'm assuming they somewhat know what they're doing, given that they actually built the thing and it actually works.  Gotta give them some benefit of the doubt for that.<p>Another speculative data point, a vehicle like this, the engineering is a much bigger % of the final cost than your standard "build what we built last year" car..  that has to come into the decision as well.