I have seen these in the magazines a few times. It just popps in to the square hole on the trailor hitch of the truck. Quad is on two ramps sideways...

Anybody seen or have this? I was thinking of making one to fit behind my Grand Cherokee.

 

I have made a couple of them for myself and a friend. They work ok but what I have found is that many vehicles are not sprung solid enough to carry the weight (depending on what quad you will be carrying. A quick test to determine if you might want to use one is to install a 2 inch square tube in your receiver approx 48 inches out. Get a couple buddies and yourself (to get close to the quad weight) and stand on it. Putting 500 pounds of tongue weight will squat most vehicles down a lot more than you might think. It will also negatively change the handling characteristics of the vehicle. There is the option of adding leafs to the springs but that will stiffen the ride all the time. Or you can add air shocks and increase air only when using the carrier and still retain the same ride quality when not using it.
Overall I would say its ok for the occasional short trip, but with my vehicle (Tahoe) it is a hinderance to access the rear cargo area because it blocks the rear doors. On an open box pickup its not as much of a problem but then if you have one its just as easy to put the quad in the truck. I am sure that I will have some guys who have them disagree but these are just my experiences with them. They are however good for carrying alot of other things.
Just my thoughts....... Trailboss450