The basic procedue would be to make every part that has to move a group in Max (pick by element or polygon and then detach), export as an OBJ file and then bone them in Propack, I have no idea how to do the later, as I only work in Poser 4. In P4 this would be done by importing a hierarchy file, the result would be a figure, you would then have to set the centers and joint parameters for every part that turned or slid. You can also use ERC to do things like steer both front wheels from the steering wheel, etc.