From Popular Mechanics:
'When Henry Ford recently unveiled his plastic car, result of 12 years of research, he gave the world a glimpse of the automobile of tomorrow, its tough panels molded under hydraulic pressure of 1,500 pounds per square inch (psi) from a recipe that calls for 70 percent of cellulose fibers from wheat straw, hemp and sisal plus 30 percent resin binder. The only steel in the car is its tubular welded frame. The plastic car weighs a ton, 1,000 pounds lighter than a comparable steel car.'
Apparently Ford wanted to run his Model T off of ethanol.
Rudolf Diesel, the inventor of the diesel engine, designed it to run on vegetable and seed oils like hemp. Ford originally intended his vehicles to run off of vegetable oils, stating "there's enough alcohol in one year's yield of an acre of potatoes to drive the machinery necessary to cultivate the fields for one hundred years."
However, the gasoline industry lobbied hard to keep alcohol taxes high and drop the price of gasoline. This even "coincided" with the prohibition of alcohol and hemp in the 1920's.
Here is more original footage of Ford's hemp car