The big challenge no one speaks about is the auto workers' unions which will change the cost structure to produce these cars. This cost increase is coming in the next few years.
The reason I appreciate tesla, is because it doesnt have all the legacy and baggage a traditional car manufacturer has, and thus they have the ability to try bold things. On top of it, they are doing it all in america.
The land and power are cheap, the wages are reasonable and there is not a lot of union activity.