I’m running RDSport mufflers with Fabspeed x-pipe and HFC’s. The following link includes various vids including my setup:
http://www.m3post.com/forums/showthread.php?t=328915
The system is bolt-on. Exhaust sound is subject but I love the sound of my setup, which I find loud but not obnoxiously so. In cold weather, my car is noticeably louder and sets of car alarms on start-up.