I don't like cars.   I think they're ridiculous.  

But let's be clear, if we continue to want cars for some completely pixilated reason, we do not need fossil fuels to run them.

There are about a zillion other ways to fuel them.   The best, in my view, would be hydrogenated carbon dioxide to make DME.   This involve some start up infrastructure costs, but such a cost could be covered by the creation of an appropriate carbon tax - appropriate meaning "charges all of the external cost and then some."

Suddenly you would find that people really don't "need" cars, they just think they do.