I believe the "no post" you folks refer to between the front and back side windows is what used to be the distinction between a "hardtop" and a "sedan" (post between the front and rear windows).
We tend to think of sedans now as four door cars. But I remember growing up during the muscle car era (my Father owned more than a few muscle cars), my Father pointed out the difference between the hardtop and the sedan (regardless of how many doors the car had), and the reinforcement necessary to stiffen the car in case of a roll-over. We see similar frame/body reinforcements made for convertible models offered now, as well as integrated roll-bars.
Two seaters or 2+2 seating cars were referred to as "coupes", where the car was sportier, and the rear seats were more an afterthought than a car that could seat four (fairly) comfortably.

A hardtop always looks better than a sedan, whether it has two doors or four. It gives the car a "chopped-top look".....but that's just MY opinion (and we all know about opinions)!