Making a car out of hemp is not a new idea. First saw an article on a hemp car in Popular Science and went looking for more info on the intratubes. Was surprised to find out about the Ford hemp car. Ford made one back in 1941.
The hemp fiber makes it lighter and is cheaper than either fiberglas or carbon fiber.
When you no longer can use the car, instead of sending it to the junkyard, you can smoke it!! Win, Win.