1967 barracuda 383 4spd on CL

for Mopar anyway, 67 was a little early for rear spoilers. I believe the 66 or 67 Hemi Chargers had a very rare, optional, short, little sheet metal spoiler on the rear deck lid. I've never seen one in person, but I have seen several in pictures. The 68-69 B-bodies had a little "ducktail" built into the top of the rear quarters/decklid. Of course, with the famous 69-1/2 Daytonas and 70 Superbirds Mopar went with front and rear spoilers. The AAR & T/A had rear spoilers, and optional front spoilers, and most if not all the e-body models had optional "go-wings".
The concept show vehicles probably had all kinds of integrated spoilers.