I recently posted about Robert Zubrin's book Energy Victory, which advocates mandating all vehicles sold in the U.S. be flex-fueled (by which he means not just supporting ethanol and gasoline, but also methanol). The link above also describes some legislation supported by an organization he mentions in the book that includes flex-fuel and automotive prize provisions.
In a Space Show interview, Zubrin mentioned that the publisher is out of the book for now, and at the moment amazon.com still shows that it's out of stock. That's too bad - making a big post on a book you can't get. You can still get an overview of the idea, though, in the following interviews.
The Space Show - Dec 18 Zubrin interview, mainly on Energy Victory, but also linking the proposal to space efforts.
C-SPAN2 - 10:00 EST, Dec 29, Zubrin talk on Energy Victory at the Ethics and Public Policy Center
C-SPAN video library - I think this is the same talk that C-SPAN2 is playing tonight. In this case you can watch it on your own schedule on your computer.
Your mileage may vary -- I find his arguments that rely the most on his technical background rather than world politics or predicting the secondary results of the change to be the most convincing. Try to get to those parts.