Max Chen built this shopping cart soapbox car for the 1999 Sandhill Challenge:
First made for the 1999 Sandhill Challenge, then adapted to the more dangerous and curvy SF Illegal Soapbox Society. Clocked at 49 mph, has been through multiple crashes, has sent me to the hospital, and has finally been retired after parts were canniballized for a disco limo and Spincycle. With all of its notoriety, for some reason this car does not have a name.
See more of his artworks here: http://oilycog.com/artwork.htm (The "rideable" artwork gallery is awesome!) - via Make