Diego is correct. The 72 GTO in the Musclecar Review article had its rear wing installed much later (1980's), but it is a real GM rear spoiler. I guess technically, it's not a factory freak. The ducktail spoiler is reproduced now, so you sometimes see them at car shows on a 71 or 72 Lemans/GTO.
I don't know what happened to this 66 GTO, but this was the car Pontiac used in their original 1966 ad. It's wearing 8-lug wheels, which were never available on a GTO.