An older study in Sweden says this might be a bad idea. It shows there's a reduction in car damage, but that's largely transferred to the passengers themselves.

Unfortunately I can't find the original study but here's the summary

Increased risk for injury. Vehicles equipped with a hitch or tow bar receiver hitch have a 22 percent increased risk of causing severe occupant whiplash than those without hitches.

Increased risks of impact force. The occupants of the front vehicle were thrown an average of 2.5 times farther forward than those in the rear-impact vehicle. In other words, when the rear vehicle travels a mere 5 mph during a collision, the passengers in the front vehicle will feel the force and be thrown forward at a rate of 12-13 mph. This is important to note, as rear-end collisions that produce changes in acceleration below 12 mph cause the majority of crashes resulting in neck injuries.

Decreased risk for vehicle damage. Since the majority of the impact force is carried through the vehicle frame, these types of accidents often leave little physical damage to the car itself. Although this may seem like a benefit, insurance companies can use the lack of property damage to cast doubt on the severity of your physical injuries.