https://en.wikipedia.org/wiki/Volkswagen_Beetle#Wartime_production

Due to gasoline shortages late in the war, a few "Holzbrenner" Beetles were built, which were fueled with logs of wood. The logs were converted into combustible gases using pyrolysis gas producers located under the front hood, so the car could retain its carbureted Otto engine.

Still, I would love to drive a Tesla in the carpool lane towing a diesel generator rolling coal🤣😂