Create a Car Passing Shaky Bridge and Bumpy Road with "Box2d"

This is a interesting try of box2d library in Processing, aiming at create a weird shape vehicle which is good at climbing up mountains and shaky bridge.

The project plays around box2d's surface object and designs the mechanism of the car's body. The shape and the mass decides whether it can successfully pass the bridge. My design makes it very stable on the shaky bridge, so that the car is not easy to flip on the bridge. But it also decrease the speed of climbing up the mountains because of the heavy mass of the back part.