This Is The Audi A8's Naked Space Frame

Back in 1994, Audi was the first mainstream car manufacturer to switch to aluminum from steel in order to save weight while improving rigidity. The original A8's frame weighed 548 pounds. The current one's weighs 509 pounds, and is composed of 13 different aluminum alloys, which makes it 40 percent lighter than if it were made out of steel. Clever.

Photo credit: Audi