biofuels in significant quantities only make sense if they do not compete with food resources. This would suggest they are restricted in quantity by taxation and only biofuels from waste and wasteland grown crops like algae should be non taxed.
I believe that electric cars will run for a long time with fuel cells. so liquid fuels will remain on scene for some time. making every effort to build low consumption cars with ICE economically is the challenge for the next 10 years while basic research in other fields is done. high mpg cars should be classed according to seating capacity.