Attached Link: http://www.sixus1.com/products/BattleBuggyTest.AVI

Wheels are set up on the figure with a relational rotation system based on ERC. What this means is that the ZTran position of the body part called "Buggy" directly controls the Xrotation of the wheels. If you select "Buggy" and move it either with the tools in Poser or with the Ztran dial, you should see wheels turning. The link is to a viewport rendered animation test showing an example of both the wheel rotations and steering in action.