I've considered getting them for my car. Before you jump on my about it, lemme explain.
My car is a 1991 Mercury Sable. The paint is fading. The trunk pops open when it gets above 85degrees. The right taillight had to be replaced, but we couldn't find a match, so the tail-lights are different -- one has a chrome strip, nice molded plastic, cool patterns for the lights, the other is from a cheaper model, no chrome, and all boring rectangles.
The paint is fading in places. There is rust by the leading edge of the passenger side front door. The car is so badly haildamaged that it makes people laugh. There is a nice fat dent in the trunk (not my work). Both front and rear bumpers have other car's paint on them (not my work).
Its the running joke among my friends that my car is a POS but is still better than their cars (1996 Saturn Wagon, 1988 Olds, the like), so bullet holes would be the next logical step.
I would never put them on a 'nice' car.