Way back in the 1930's, Henry Ford was working in the alterative fuels sector, and in 1941 he constructed a hemp fueled, hemp bodied prototype car. The "plastic" body panels were composed of 70% cellulose fibers, including industrial hemp, mixed with a resin binder, and apparently they were as strong as steel.

But because growing hemp in the United States was essentially outlawed in 1937 because of its association with its THC, it was impractical for Ford to mass-produce vehicles that relied upon a steady supply of it.

Ford said and I quote "Why use up the forests, which were centuries in the making, and the mines, which required ages to lay down, if we can get the equivalent of forest and mineral products in the annual growth of the hemp fields"?

Perhaps hemp was outlawed because it was dirt cheap and they wanted a huge profit center for the new automotive industry.