Great review! I really enjoy this set as well AND was able to add a working steering wheel by connecting a universal joint to the bottom of the wheel. Then, place a 12t bevel gear onto one end of a 3l? axle and connect the other end to the joint. Secure this structure in such a way that the 12t gear meshes perpendicularly with the 16t gear directly below on the floor of the cabin.
It isn't the most elegant solution, but does work!