Most of my frustration came from the trailer itself jumping towards its side when the angle got too great, as if there wasn't any weight in the trailer nor grip to the wheels. As far as I can tell, the forces acting upon the vehicle+trailer aren't taking into account the hitch's own rotation and forces that applies. Also, probably the biggest contributor is that the there is no actual state to the turning direction as you would in a real vehicle (e.g., the tires turn to face a direction and remain there until you counter-turn them).
I think most of my gripes would be solved by retaining wheel turn state and making the trailer more weighted or have it have a higher drag amount when lateral force is applied. Not certain what your model is, just some thoughts.