id like to know this also because I want the x5 to sound a bit nicer then stock

I did put a supersprint catback on my e36 and at first it was loud then it calmed down after a few weeks

__________________
2014 Jeep Rubicon unlimited 3.6
2005 X5 4.4i
2002 Jeep TJ 4.0 SOLD
1997 328I 4 door 2.8 SOLD