The Soybean Car,” a concept developed by Henry Ford -- is an example of an unrealized dream. The car was intended to run on hemp fuel.
According to Wikipedia, “The soybean car was a concept car built with agricultural plastic. The New York Times in 1941 states the car body and fenders were made from a strong material derived from soy beans, wheat and corn...Because of World War II all US automobile production was curtailed considerably, and the plastic car experiment basically came to a halt. By the end of the war the plastic car idea went into oblivion.”