I recently added a 2004 X3 to my fleet of BMWs. So far, I really like the car (my daughter will be driving it). I am, however, somewhat baffled by the exhaust baffle on this car. I did not really notice the deep, throaty exhaust note of this car when I test drove it, but it was the first thing my wife noticed. So, I figured the vacuum line to the valve on the muffler was cracked (or disconnected on purpose...i.e. - golf tee mod). When I climbed under the car to investigate, what I thought was a piece of broken vacuum line was actually just a rubber cap on the valve. I figured, no problem. I've got 20 feet of vacuum line in my tool case, I'll just replace the missing piece and the car will be nice and quiet so my wife can't hear me coming. Problem is, I cannot, for the life of me, figure out where the original vacuum line was routed or where the vacuum actuator for the muffler is.

My question is this: I cannot find any old vacuum line or an actuator anywhere under the car and no evidence of where a vacuum line would have been routed. I've looked in all the normal place inside the rear of the car (both sides, all around the spare tire). Can anybody tell me where it might be? I have scoured the internet and can find the location on later model X3's but no luck when I look in those places in my 2004. Any help would be greatly appreciated.