I got my 03 GT about a month ago. I installed a MAC CAI already. My future mods are TB, Plenum Cams gears.... But for now i want to start with the exhaust. I'm looking for a Catback that's gonna have that rumble at idle and that low agressive mustang sound through out the entire RPM range. I want a little louder than average but nothing crazy loud. Being in NY I need to stay with Cat's once i do my H-pipe. But anyway I was thinking Mac or Magnaflow but open to all options please let me know what you uys think. Thanks for your help.