Here are the details:
Not much louder at all, but sounds better, the raspiness that was there under acceleration and revving is gone. Just a nice deep rumble.
My exhaust is: from engine to cats, to muffler, out the back......
Muffler: Flowmaster 50 series dual inlet/outlet (524554).
Info on Summit Racing website NOTE on the mufflers, the OEM ones are HEAVY!
Tips: Magnaflow (35167)
Info on Magnaflows website
Parts and install put me right around $500. I'll get pics and sound clips up as soon as I can.
Here's the thread, the first few pages are OK and then the thread took a turn for the worse.
http://www.xoutpost.com/x5-e53-forum/...ght=successful
Let me know if there is anything else......