Dental work - Andrew Hamilton
Thats why I never would buy a new car. Twice I saw careless drivers hit my towbar when parking behind me. It damaged them not me! Towbar hardly sticks out and ball is at about 18in height on van.
In supermarkets I see doors often flung open until stopped by next car. Car occupiers tend to be young with well used vehicle. Damage visibility depends on paintwork and you would notice it more on your car than others! Only protection is a wide sidestrip which would look untidy.
Dental work - Armitage Shanks{P}
Plus, to get as many cars in as possible, supermarket car parks seem to have spaces that are too narrow for the average car with one door opened on each side to let driver and passenger out.
Dental work - volvoman

That's the best possible reason for having a tow-bar in my opinion - it certainly focuses the minds of those who might otherwise be tempted to get too close ! The supermarket parking space issue is an important one since a great deal of damage is done to cars because there simply isn't sufficient room to get in/out of the car once parked. 3 door cars suffer most of all due to the size of their doors so I try to avoid parking next to these if at all possible.