Pop the GL450's power tailgate to find helpful power-folding third-row seats that create a generous amount of room with the touch of a button. Removing the lightweight metal cargo cover is a hassle, and it's too long to store flush against the side panel and still close the tailgate. Under the cargo floor is a temporary spare tire and a well where items can be stored. Flip the second-row seat cushions forward and flop the seatbacks down to create a relatively flat, carpeted load floor. Watch the overhead climate vents, though, because they're likely to get in the way when loading large items. The rounded cargo opening also limits the size and shape of items that can be placed in the GL.