I think the Series Hybrid mode that Mitsubishi Outlander PHEV has is very interesting. I think they could very efficiently run a car in Series Mode using propane to power the motor and have very respectable mileage.
You do have a point--that with only 5 seats, there is not a lot of passenger hauling difference (plug in minivan, anyone?)--but I think the real difference they're shooting for with the Mitsubishi Outlander PHEV is having an all-wheel drive SUV that's capable of off-roading or 4-wheeling while...
It does seem essential to have a resistive heater to heat the car otherwise you would lose all the benefits of having a plug-in hybrid in the winter months. I have looked to see what kind of heater the Mitsubishi Outlander PHEV has, but have been unable to find the answer to this question.
$34,000 is not a bad starting price for the Mitsubishi Outlander PHEV. It would be one of the cheaper plug-in hybrids, as well as being the only SUV on the market.
It sounds like the Mitsubishi Outlander PHEV has a fairly standard ABS anti-lock brake system. I would be curious to know if it has predictive anti-lock technology.
The Mitsubishi Outlander PHEV is on sale in Japan and this article talks about the fuel efficiency based on their numbers. They said the 148 mpg will likely be around 80 mpg by US standards.
http://insideevs.com/mitsubishi-outlander-phev-on-sale-in-japan-today-extended-promotional-video-released/