So I ended up rerigging this thing, and after enabling physics, and getting this tank up and running/driveable, i see how you can not use the physics to effect the bones to then effect the mesh. Hope that made sense.

I guess I want to take this a little further which is leaving me no other option than to fake it, so after digging around for a bit, I cant seem to find a way to pull in a bones location from the world and adjust it accordingly? Is this even possible? Or adding additional collision boxes to bones or seperate parts of a single mesh, or is it only one per entity.