WarpedOne

I wouldn't say the sky is falling. Elon already said Bluestar project will be harder to pull-off than the Roadster or even WhiteStar. 30.000$ target price means the price of batteries will have to come down considerably. With 6% annualy price decrease in the following 5 year time, the roadster battery price will only drop from 20.000$ to 15.000$. That is still the half of the whole car (Bluestar). Tesla is serious about the project so they are looking at all the options. Maybe they are thinking about halving the battery pack (and so it's cost) and offering an optional range extender trailer with some additional cargo space?

The trailer could have permanently mounted ICE electric generator with no gearbox and no transmission. It would only generate electricity at constant power and fill the main car batteries. Its efficiency could be quite high (relatively to ordinary ICE cars) and when not needed (normal daily city driving) it could be easily left at home.

Actually such a trailer offers additional flexibility over onboard ICE. Some customers will do fine with onboard battery pack only and won't need and ICE helper at all. Why force them into paying for it? The trailer could be made a standalone product fittable to more than one single model. Same trailers for Whitestar and Bluestar? Also more than one model could be made:
- trailer with only ICE generator
- trailer for "longdriving" with more powerfull generator and some cargospace
- ...

In this way Tesla Motors would still qualify as a pure electric car company. All reasoning Martin has done would still hold.