I have hi flow cat DP and MPE. Sound file of my car :-
http://www50.zippyshare.com/v/Q7E8noNa/file.html
BCS here in the UK make a turbo back exhaust. Another sound file of a different car with same DP as mine on the move...
http://www58.zippyshare.com/v/uyKt43wp/file.html