I'm not a modder, but with weird stuff it is good to experiment and learn from it. ;-) I haven't looked at the wheel and pedals yet, but basically it is just a d-series frame but with node-offset for the cab and some of the parts. (Thanks to Fillman86 on Youtube for that tip!) They are still attached to the front in-game which makes it wobble around a lot, so they would need modified .jbeams as well (edit: typo)
I still can't get the steering wheel in the correct position and I'm out of ideas on how to fix that. The pedals are in the correct position and working, body is raised a bit to stop it from vibrating, new beams to connect it to the frame, radiator and engine parts moved back to the original position. They were attached to the body so I had to move the radsupport slot to the frame. (that also means some parts are floating in the air) With all that weight in the back it doesn't have the greatest handling but it's fun to slide it around. It is fully functional, but with the floating steering wheel it looks even stranger then it already does. Edit: the bonnet doesn't open either.