Found these couple of links on the Kneeslider to a couple of different options on green vehicles.
The first, is cars running on compressed air - nothing new but they seemed to have upped the efficiency and got on board compressors for recharging. Sort of a fossil fuel/compressed air hybrid.
The second, I really like - a guy converting big yank tanks to biodiesel but also using a few other tricks like hydrogen to really increase the efficiency & performance. Like the idea of having performance with economy.
Personally do not think batteries are the go but perhaps could see myself on a diesel Concours if it's quiet, smooth, powerful & economical...