I've got one on my Comet, even has a genuine "Shelby" chromed trailer ball on it. Got to be good for an extra 10-15 hp.
Yep, I've seen them also. They bolt on to the bumper if I remember right. Not made for anything really heavy.
Yea, just a class I hitch. I use it to tie the car down on the trailer and also to lift the rear of the car with my shop hoist. I did make a run to the tire shop with my aluminum utility trailer to carry the spare set of wheels and tires.