Like I said on my first post,if you SEARCH for 3.0d exhaust silencers,you will find plenty of useful info.
If you want to go for the "dummy" look ,then here´s a thread by our friend Fullmetaljacket,showing how  you fit any type of tail pipe you fancy.
http://www.xoutpost.com/bmw-sav-foru...ack-smoke.html