Clearly, you won’t be considering a coupé if space is your number one priority, but the RS5 isn’t as impractical as you might imagine. A couple of six-footers will fit in the back easily enough, although they’ll have to slouch to keep their heads from brushing against the rooflining.
Officially, there’s more boot space than in a 4 Series or a C-Class Coupé and, while the differences are small, the A5’s load bay is certainly usefully squarer than those of its key rivals’. Rear seats that split and fold 40/20/40 are standard, and when down they leave only a gentle slope in the floor of the extended load bay.
Front space is much better; even if you’re extremely tall you’re unlikely to have any complaints about how far your seat slides back or how much room there is above your head.