Steel has been the backbone of automotive manufacturing for a long time. Lightweight alternatives like carbon fiber and aluminum are starting to pick up in prevalence as well, but what are some of the most bizarre materials companies have used to make cars?

The Swiss-made Rinspeed BamBoo concept only used "bamboo fiber" in the interior, but I'd say it was a pretty brave leap to consider nature's flimsiest tree as a car component at all.

Let's see the other odd and unusual composites you've seen put to use in car construction.

Image via Rinspeed