The 3gt we had for lease wouldn't work as an SUV. The 3gt was 3 across the backseat (unlike Nicks reference to the original 5gt), but the sloping gate made it a no go for our dog in the trunk area. I don't think the 5/6gt would be any better in that regard.
That car made it so painfully obvious that BMW shit the bed not making that f30 long wheelbase platform w/ the N55 the baseline for the 3 wagon. It rode well, the extra leg room in the back seat made 2 adults back there quite comfortable, the drivetrain w/ the 6 cylinder was nice, but the back end was completely worthless. Worst of both worlds, none of the space of a wagon, none of the security of a real trunk.
I know I posted a pic on here of Mabel in the back for reference to how poorly she fit.
edit: to Nick's point, the middle of the rear seat still has a big hump on the listing you posted.:
