This whole project started off as a modelling exercise but once the modelling part was done, it would be a shame not to make it move as well. As shown in the video below the rig features ground collision, dynamic parenting and dynamics.
There are little controls on this rig as most of the animation is handled by systems that are easily tweaked by adjusted a few variables. The dynamic parenting makes is easy to keep the aim of the turret or machine gun on certain targets and switch between them. The thread length is always maintained by the front wheel moving forward or backwards depending on the length of the curve.