Im looking into replacing my exhaust with an axelback exhaust on my 2008 GT/CS 5 spd 4.6L. First whats the difference between catback and axelback? Also, for now all Im wanting to do is just make my car louder. Would I benefit more with getting H-Pipes or does my car alread have them? Or should I go ahead and get a CAI with the tuner and the exhaust?