To give you an idea how rare they are, I went to the Eckler Camaro/"f" body car show this past fall and there were only 2 cars there out of 160+ that had the fold down rear seat, mine and one other. So all in all there arern't too many first gen "f" bodies out there with them.
In addition, it is unreal how many people are attracted to this silly option. When I was at the Daytona Turkey Run this past Nov. it was amazing how many people were drawn to our car as soon as they looked in and saw the rear fold down seat. Crazy how something so basic and really kinda silly can be such a big deal, I guess it's just the cool factor thing...