On our Simpson trip in 2013 we saw a Navara D40 at Dalhousie springs with a bent chassis. It had been towing a hard floor camper with the longest draw bar I had ever seen. Not sure of the make.
This camper had 2 large boxes on the front (Tool + fridge) and then gas bottles. The wheels where near the back of this contraption so depending on what he had stored in there (generator? chainsaw? etc) the weight would have been on the rear of the ute. Not sure what he had in the tray either.

I think its good advice even though I have not followed it. By the time I had put all the bar work and drawers in the wagon my tare was up over 2.8 tons. Still don't know what I weighed when I left Adelaide fully loaded.