Here are some videos showing the rigging I created and used for the vehicle animation on the Race Driver 3 FMV.
The Go-Kart rig consisted of three keyframed bones; one for the Go-Kart's movement and two for steering. The steering system used one bone on a spline path leading the Kart which made good for automatic steering and one to allow me to keyframe extra steering when needed. Other vehicles tthroughout the FMV used a similar rig with added parts when needed.
Single bone keyframe animation showing the Go-Kart steering rig
Whilst the steering system is similar to the Go-Kart, the Monster Truck needed a few extra bones to work the exposed suspension system and opposed steering on fornt to rear wheels; keyframing seven bones in total.
Monster Truck rig demo
and here is the Monster Truck rig in max viewport
a video showing a Baja buggy race