WOW!! I feel as if I have a whole new car!. I finally got around to installing my SS X pipe to my Dinan exhaust and I am one happy camper!
Aside from the sound sounding a lot more aggressive, I can honestly say that I have noticed an improvement in throttle response. I know some of you have reported the same thing but I didn't think it would be that much of an improvement

. I installed the pipe just for sound, turns out I got more then I expected!!
I was a little worried that I would see my check engine light turn on. Nope, so far so good. All in all, the car "FEELS" quicker and sounds a whole lot meaner. Also, it feels as if it breaths a lot better. I am so happy, I recommend this modification to all who own an M5. IT'S MUSIC TO MY EARS!!!!
I asked my mechanic to take her up and down the street for me to hear, simply amazing. I now see why you guys went nuts over the X pipe

!!