were all 65-66 fastback backseats fold downs?

I've never heard of a 1965-66 2+2 fastback without the fold down rear seat, was there ever an option to not have the fold down seat? What would you get instead? I'm asking because I'm looking into buying one this year and all the ads I've seen keeps pointing out that they have the fold down rear seat. I always thought/assumed all fastbacks had that kind of rear seat...

thanks, and have a fun weekend!