here is a clip of the the sport on an X5M. I think the race sounds better. this one is too tame :p

BMW_X5M_Eisenmann_sport - YouTube

I really want to get the eisenmann exhaust too but that's a lot of coin for just an axleback.

lemansx5, when you say best bang for your buck for the X pipe, is that in terms of sound or performance? ty

I have a dinan exhaust and love it. The only problem is its expensive compared to other exhausts

not compared to eisenmann and supersprint. i would consider dinan but want to retain the stock look. i don't care for the round tips.

I have Dinan exhaust on a 2002 X5 4.6. Absolutely GREAT sound, can hear it just enough under throttle and great under full throttle. At cruise it is quiet and does not interfere with radio or conversation, no drone. You will also gain some HP and torques due to lower back pressure. It would be the first thing I would do if in your place.

Good info. Thanks to all for your comments.

Both. This mod is more suited to 4.8is than 4.6is. Quite a few people here have done this. Search on X-pipe.

i have heard both pros and cons with the x-pipe. i understand that placement is essential or you will lose power. is there any science behind this mod or is it just for more noise?

I believe there is thread here on pros and cons.
Yes, placement is important. I did not notice increase in performance as in more HP. I guess back pressure reduced due to resonator removal.

Xpipe installed for $150 and it sounds good..

I actually was planning on getting the dinan exhaust. my neighbor has it on the 550 and it sounds amazing. Its not too angry and raspy just perfect when he cruises you can barely hear it, once he jabs the peddle a bit you hear the angry roar. I just dont like the round tips, they look pansy to me. otherwise i would have gotten it a while back.