There's 52.6 cubic feet of maximum cargo volume with the seats folded. (cars.com)
Maximum cargo volume in the Gran Coupe is rated 45.9 cubic feet with the rear seats folded flat, which is significantly less than the wagon, at 53 cubic feet, and the GT, at 56.5 cubic feet. (cars.com)
When maximum cargo volume is required, the bottom cushion moves forward and down into the rear footwell area, which in turn allows the seat backrest to be folded completely flat and onto the same level as the trunk floor. (topspeed.com)