There have been cars that run on alcohol (E85 specifically) for several years now. Because E85 is funded by government grants, it's in limited supply with very little motivation to really ramp up production. From what I've read, E85 won't be cost effective against gasoline with out government subsidies until gasoline reaches $3.50-$4/gallon. Even though many folks consider $2.50 gasoline expensive, in terms of real cost, it's still cheaper than all alternatives. Once gasoline hits $4/gal, then we'll see biofuels take off because they're finally financially viable without government assistance. The good news about E85 is that it burns imaculate compared to gasoline, so once we do make the switch, tailpipe emissions nearly vanish entirely.