88 coupe: I am not a moderator on this forum, but I have read a few of your posts now and I must say I don't like your tone.
Oldsmobile did in fact use the term Sport Sedan for some of its pillarless hardtop sedans from 1961 through 1964 - possibly before, I don't have my literature in front of me to verify. Holiday Sedans, such as the '61 I previously owned, had the small triangular windows in the back (as did the later Luxury Sedans). Sport Sedans (I am guilty of incorrectly referring to them as Sports Sedans, too) did not have the the triangular windows. They either had the cool-looking wrap around rear window in '61, or blind rear sail panels from '62 through '64. Oldsmobile referred to them as Sport Sedans, in print, and on some of the vehicles themselves. The literature that was submitted was not just "printed by an ad agency." It was printed by Oldsmobile Division of General Motors for use by its sales people in the field. The term Sport Sedan also appeared in dealer showroom albums, sales brochures and, I believe, parts catalogs. And, Oldsmobile put the name in chrome on the cars themselves, as evidenced by the car in question:
My Holiday Sedan had a similar badge that said, of all things, HOLIDAY.
Now, I believe someone is owed an apology.
Paul