Rear of Dark Aero is 22" tall x 39" wide = 858 square inches.
My truck rear end is 39" tall x 72" wide = 2808 square inches.
858 ÷ 2808 = .3055555555555556
So 30.56% of the original area of the rear of the truck including the rear wheel strakes and rear diffuser. About a 69.5% reduction over 7' of boat tail.