You are absolutely right, Aslanefe.
From what I gathered in my readings, this tape stripe was not exclusive to Grandes. Apparently, it could be ordered on other coupes as well as part of the sports appearance group.
I just couldn’t find a pic of a non Grande coupe with said tape stripe.
I also saw a bunch of Grandes without the stripe, or even a vinyl top. Seems like you could virtually order any combination of options on any model, back in the day.