Contraptions are generally art cars that no longer look like a car. In most cases, the art car is built on the chassis of a vehicle simply to utilize the wheels and the steering. The car itself is removed or heavily modified, and then on top of it is built something entirely new.
We have many contraptions in the Art Car Experience, including Pop Art Cart - which looks like a rolling movie theater popcorn machine, Hen-A-Tron - an enormous metal chicken, Roachster - a giant metal roach, and Spooter: A Spider Scooter - which is exactly what it sounds like.
Big or Small, Contraptions are those Art Cars that sometimes your mind just can't wrap itself around.... wait, did I just see a lifesize triceratops rolling down the street?