As evidenced by numerous threads in the subject, there are many ways to skin this cat. Here's mine.

A 48" piece of 2" black iron pipe rests over the 2" ball on the receiver hitch. The pipe is supported at the top with two ratchet straps, while the Speer is hung from the hook from an old ratchet strap.

Ordinarily, I would anchor the support straps to hard points in the bed of the truck, but in this case, I wanted to illustrate what I consider to be the best way to take the horizontal load of the hammock on vehicles other than trucks. The straps are passed through the open back doors and hooked to each other. The straps are then snugged up, and the doors are closed. This is a very strong arrangement, and will not damage the vehicle.