The ultimate green car would be a bio-diesel pluggable hybrid. It would have solar panels on the roof, trunk, and hood. It would also have a hand or bicycle generator. These latter two items are for emergency and supplemental power. And of course you’d have solar panels, a wind generator, and the grid to charge it up at home along with your own home brew bio-diesel production.
This sounds more like a fantasy vehicle out of Mad Max. “Who run Barter Town?” “Two men enter. One man leave.” If you had such a dream green vehicle when civilization collapses, the first thing that will happen is you’d be killed by roving bands of thugs who’d just take it and drive it until it ran out of fuel. Then they’d push it over a cliff or down a ravine to watch it get smashed to pieces.