Despite the X6's sloping back end, the SUV has more cargo room than a two-row X5: 25.5 cubic feet as opposed to the X5's 21.9 cubic feet. The FX, meanwhile, has 24.8 cubic feet of space. If you need more room, the X6's split-folding backseat folds down nearly flat with the cargo floor to make 59.7 cubic feet of space.