Here is a Low Poly model of an M2 Bradley Infantry Fighting Vehicle. It is fully rigged up for animation including the deformable tracks. I had to come up with my own method for animating the tracks, they are made up of multiple small pieces that are attached to a circle curve via an animation path constraint. The circle curve is then deformed into a lattice that distorts it into the shape needed to wrap around the wheels of the vehicle. This way, you can then rotate the circle procedurally, and the pieces of the track will follow as they are constrained. You can even animate the lattice deformer when the vehicle goes over bumps or uneven terrain.