Sorry I'm sure it's me but what quarter vent are you asking about?
Are you referring to the simulated vent/scoop on coupes and convertibles?
The fake quarter panel scoop on sportroofs?
There isn't one in the door jamb at the front of the quarter panel like a 70 so that can't be the one your looking for.
For the future you might want to include the information about your car in your signature