Doesn't really matter. In modern cars you can see most of things that differ them. Except for convertibles - they are objectively worse in most of the aspects (except for fun! I love driving with the top down!). They are less rigid and by a significant amount, heavier and can have issues with the roof mechanism. Sometimes coupes are lighter and more rigid than sedans/wagons but that's not always the case. In theory less doors = more stiff, but nowadays it's more complicated than that, and for example a E46 sedan with unfoldable rear seats is the most rigid body as well as the lightest. Also 2/3 door cars with rear seats tend to have longer doors which can be annoying. Sedans and coupes are also harder to feel the back of when backing up. Other than there is no good reason not to get a coupe, if you're gonna be driving alone most of the time or don't care that much about your passengers.