I wonder what do you mean by obsolete, the efficiency of a combustion engine is still dramatically bad despite of the fuel being used, compared to an electric motor.
that being said, biofuels could be a nice thing to let us drive the current ICE vehicles in circulation, but just until they are totally busted and recycled.
we really need to stop manufacturing new cars, especially the one using ICE. cars are one of the most complex and wasteful product being manufactured.