At the very least, the predictable emergence of tens of millions of cars here and abroad that don't require gasoline will create a free market in various alcohol-based "Freedom Fuels" that are considerably less expensive to produce than gasoline at prices well below today's.
For example, a federal requirement that new cars sold in America be capable of using methanol and ethanol, as well as gasoline, would create markets for such alcohol-based fuels and competition that will drive down gas prices.
We have the option right now to require that new automobiles sold in this country be capable of using alcohol-based fuels like ethanol, methanol or butanol instead of or together with gasoline.