= two door regardless of quarter window placement. Hardtop is just a structure type of a Coupe. Even a t-top, targa top, glassroof, and etc are still in the coupe domain in my book.
= Hardtop/softtop/removable shell.
= Four doors, four side windows, with center pillar.
= Four doors, four side windows, with center pillar, no rear deck, hatch
= two doors regardless of quarter window placement, no rear deck, hatch
= two doors or four doors, two side windows, no rear deck, hatch or swinging door.
^just my general opinion on whats what.
RX-8 types are a hybrid type of design without the center pillar. So technicially if two bigger doors were to be made up to replace the four doors, it prolly would not compromise the original design or alter the chassis structure. So i figure that how it can be called a coupe due to the lack of the center pillar. I think its a grey area. Becuase if that was 100% true a old skool Continental could be called a coupe and that doesnt seem to fit the bill. So I can see how it would be annoying in the terms of a A7. Its modern day, streamlined Continental type car.
But after looking up this:
Anything besides a convertible can be a given the term sedan. Quad Coupe was a correct term. But GM seems to made a patent on the name since the Saturn had one. I guess we have to blame our beloved company for the liberal use of the word coupe now.