30i Engine Vibration at Idle

[imalabil]

I just don't know what to expect from a 2009 E70 30i - it isn't glass-smooth at idle in drive, there's some buzzing or light vibration felt in the body structure and steering wheel. It's a lot less noticeable when put into neutral, and goes away once the throttle is tipped in and you accelerate. Not harsh, random vibration like a miss, but more of a buzzing sensation. Sometimes some underhood panels set up a sympathetic resonance as well.

If some of you owners could comment, it would be appreciated.