From another thread I guess there are 3 versions. Going to try and get version 1 done.
Version 1 : replace the 2 big perforated pipes with straight pipe... EXCELLENT SOUND
Version 2 : replace the 4 perforated pipes with straight pipe... LOUD NOT SO EXCELLENT A BIT RASPY...
Version 3 : well make the oem exhaust straight pipe.... INSANELY LOUD... (ITS FAWKING LOUD)
Taken from http://www.m3post.com/forums/showthread.php?t=671708