Test drove the car this morning and was pretty amazed. Throttle response is quicker on both default and sport modes. The car feels lighter and easier to accelerate (no pedal lag). Rev increase is smoother and quicker. You can feel the umph from around 2000 rpm and up (more power on low, mid and high ranges). No big difference on engine noise but it definitely sounds stronger and with a deeper tone. I didn't change the filter, i've been using the K&N stock replacement all along. Im very happy about this mod. Dinan claims a 7 HP gain so I guess this mod costs around $4.57 per HP. Not bad.