About 25 years ago I answered an add in the paper for a VW for sale.
I went to look at it and it was just a ranch type vehicle. Ragged interior and pretty sad looking but I was going to make a dune buggy from the components anyway so it fit the bill.
This VW had the ball mounted on the roof with a steel plate bolted to the roof. The rancher used it to haul a 300 gallon tank/trailer from the water source to the range for the cattle. Same principle as in the video. 300 gallons = 2400 lbs and another 500 lbs of trailer perhaps, thats nearly 3000 lbs. It worked ok on his ranch, don't know how it would perform on the interstate :) :)