If we, at our company, tried to get this onto the road in Holland, the traffic inspection agency would have the following comments:
1. any 5th wheel device should be directly mounted to the truck frame. If an additional subframe is used, you need to have a calculation report of a 3D Finite Ends Analysis (FEM) to show that the assisting construction is strong enough.
2. The center of the 5th wheel coupling is not allowed to be behind the rear axle center.
3. the log of wood supporting the tailgate is obstructing the view at the license plate
4. The trailer should clear the truck cab in 90° in both directions (left and right turns)
If all these criteria had been met, the inspectors would still find something silly to stop anything from getting on the road like this