Exoskeleton Cars

An exoskeleton car has a visible external frame, being made of steel, aluminum or carbon fiber tubes.

Body styles are open wheel sports cars, with their wheels outside of the main body and each wheel covered by its own lightweight mudguard, usually carried as unsprang weight supported on the hub carrier. The chassis has four large longitudinal tubes, two on each side of the car body, inboard of the wheels. These main chassis tubes are spaced apart by smaller diagonal or vertical tubes.

More information can be found here: http://en.wikipedia.org/wiki/Exoskeleton_car