I saw a 3.0 in a parking garage when I left work yesterday and you were right, the 3.0 (not sure if there's a difference between 3.0 and 3.0si as far as this is concerned) has the black plastic wheel arches going straight down, not flared out like the 4.8i and like the aero kit suggests. The fenders are not any different, that is sheet metal and will not change from the aero kit, it's part of the rear quarter panel. The "flared fenders" that the kit refers to must be the plastic arches that are flared out instead of flat.