Ok, i know the S4 aero package has a CD of .29, and that the s5 spoiler reduces lift but increase drag, my question has to do with the front and rear bumpers. Is the S4 with aero package front bumper, or the S5 stock front bumper more areo dynamic? Rear bumpers? I cant find a any aero info on the s5 cars,... does anyone have hard data? not really looking for which one you think looks more aerodynamic, but hard numbers. Thank you.

 

they are the same