There is nothing better than having some neighborhood kids hear your blow off valve and scream "WOW YOU HAVE NAWWZZZ?" because they play Need for Speed- Underground.
Also, nothing is more fun that doing a shift under boost at ricers/fbodys and the person that was going very slowly in front of you. (mine is VERY loud and is mounted in the right front corner)
All that aside, you gotta love rolling into the throttle and getting a kick in the chest as boost kicks in.