Technically it's not allowed here but they never enforce it at all.
Many rear end accidents occur at lower speeds, not highway speeds. I've seen far less damage with the trailer hitch scenario, and in some cases no damage except for the car doing the rear ending. Typically they're braking, but not enough to stop so they hit you while still braking. At times, you won't even see a scratch. Higher the speed, more impact, you're kinda screwed usually either way. I've seen a WJ without a hitch and the back just buckled almost to the rear seat. The hitch will disperse the impact across the rails more than without and have a better chance of less damage. Still would have been bad though. Same theory is used when recovering if you're stuck and some prefer a front hitch to a tow hook. distribute the weight so you won't damage anything. Keep it localized, and you'll be ripping something out. If someone is going fast enough to bend the rails you're screwed anyways, but if not, the hitch takes the blow, initally by the ball and tongue, and the force and if it's enough to fully hit you, is distributed into the hitch, which is quite strong and thusly into the rails. You would need enough force to put through the hitch and then into the rails to bend them, in which it would be written off anyways. Without the hitch, it would go into the this metal bumper behind the fascia, which is meant to crumple and cause more force into the back and rails as they're taking it directly rather than the heavy sides of the hitch bolted into the rail.
The beatings will continue until attitudes improve!
HID Quad bi-xenon + foglight retrofit