I have one on my jetta. I built it myself because I wanted a 1-1/4" receiver and not the 2 x 5/8" flat bar type. There is only sheet metal behind the axle, so you won't be welding much there... I bolted mine through the inner surface of the 2 rear sheet metal "frame rails". Three 3/8" bolts per side with large fender washers have held it for a couple of years of heavy use, sometimes towing more than would be considered prudent...
MacGyver has a bolt-on "hidden hitch" brand hitch. He likes mine better as it's far more hidden... I've looked over his hidden hitch and it appears to be a well constructed unit. It has the flat bar type receiver, not sure of the rating.