I agree with Charles that Elon Musk is a clever business men - full stop!! There are so many problems on this planet to resolve and I do not understand that we require to go to Mars when actually we have so many urgent issues here on Earth to build and resolve.???? Besides all that its pretty arrogant to talk about energy conservation or efficiency when his own car has more energy inherent energy-content and a battery that cannot be recycled that I have my most urgent doubt with his car in general.