It's a great idea (in fact all of the above are) as it's been bugging me for some time, even as a stude. I don't really like the idea of getting a PPL to fly around the country under my own steam but still be reliant on friends to pick me up from their local strip.
Surely the main winners are the airfield operators? If you knew that you could fly into field A or B, but that B had an ickle car to get around in you'd go for B every time. The airfield operator would have the keys and it could be part of the PPR chat.
The electric car idea is great as there are less overheads (no road tax, no petrol) but there are a few gotchas - where and how to charge it, how often users are likely to run out of juice because they're just not used to it - that make me think that again an airfield operator would be most likely to make it work (or make it fail if it's not their idea).