The "step" in the rear is just me playing with shapes and design. I guess it may reduce the benefit with Kammback shapes but it doesn't need to be as deep as in the picture. When I extrapolated the different body lines of the Saab I noticed parts of nice teardrop shapes. Playing with these lines led to this particular design where the rear lights in the extension protrudes to the sides, reminding of a whale's tail or the wings of an airplane. Hmm, the guys at Saab were aircraft designers from the beginning, so...
