Comment by vessenes

Well, Elon said the final prod car would be lighter; whether or not they achieve that goal, the strong implication: the car has a battery and power train in it. Also, we saw it drive up the first part of the ramp without any air seeming to come out the back, and reverse down slowly; there don't seem to be forward facing fans/jets from the looks of the air coming out. I'd say Occam's razor is that the car has a full electric system in it.