[thinkaboutit]

Perhaps using the rear window as a stressed member of the chasis makes a coupe body more rigid than a hatch? Combined w/weight savings for coupe (no separate rear window frame/smaller rear window) it may make a noticeable difference in handling.

That being said, I do like hatches better b/c I can easily fit bulky items like a surfboard or bicycle through the back. Toyota should consider cargo/passenger space in designing the FT86 b/c it's the only significant advantage it will have over a Miata since they are priced the same now.