A liftgate assembly for a vehicle includes an outer panel and an inner panel. The outer panel is adapted for mounting to a rear portion of a vehicle and includes first and second lower corner regions. The inner panel is mounted to the outer panel such that the outer panel and inner panel define an opening for a rear window. The inner panel includes a first reinforcement rib diagonally extending from the first lower corner region to a Z/Y center adjacent the opening and a second reinforcement rib extending from the second lower corner region to the Z/Y center. The reinforcement ribs are arranged with the outer panel to define an A-shape or inverted V-shape.