First of all, I know that we would hardly be able to make Gasoline or Diesel for cars - that’s not what I was thinking here. So away with you, trolls!
Now, to the Idea at hand. I recently watched an older episode of myth busters, where they used >Moonshine< as fuel for vehicles. Moonshine, as it stands, is apparently up to 92% pure ethanol. Now looking a bit further, there is Ethanol and Methanol fuel for Race Cars, and normal Gasoline Cars can handle Ethanol based fuels.
Considering this, one could add new Engines, working with Ethanol, or modify the old Gasoline engines to accept high percentage Alcohol/Ethanol as Fuel-source or fuel additive. Ethanol, as it stands, should probably have a higher power output, but it would also burn faster.
Now, if one would add Ethanol-based Engines, why not make a rare multi-tile building like a Racetrack, with several, partially crashed, Race-cars. You could even make differnet Racetracks with different kind of vehicles ; that could be a good source for fast or powerful cars or car parts while being outside of a town.
To make it more fun, some extra-rare car prototypes could be added to the game as well, powered with a reactor or something like this ; Hell, some cars could even have weapons, considering the state of the USA in the backstory 
Opinions on this?
Would it even be possible to fill a gasoline-tank with ethanol additives, like if you add sinew to a sewing kit? Could it keep track of the % of Gasoline and the % of ethanol and react accordingly? The more Ethanol is in there, the harder it is to start the gasoline engine (because it’s not optimized for Ethanol.). This could potentially make for interesting scenarios, where a horde of zombies is closing in and the engine just wont start
