This problems has been plaguing me for years. The dealer tells me he sees it "all the time" and claims it's normal for most 6 cyl bimmers. I'm going to my garage to check it out right now...
Edit:
I checked it out and couldn't find any cracks where you had mentioned. This noise is driving me I-N-S-A-N-E, and what's worse is the shop foreman at my local dealer claims it's normal for most all 3.0i's. If it's normal, then it's a desing flaw. These cars shouldn't make this noise. Does anyone have any other info on this issue? I'm really losing my patience and am about to take it to a independent shop to take the air intake piece by piece to see what the issue is.
P.S. - The dealer claims it's turbulence in the air box or the throttle body. Anyone hear of this before?
I just snapped these photos for better reference.
