Here is another pass at just the noisy passenger side from a cold start. Lighting sucks, but it's the sound we're after here. I came in and down by the filler, ran along the cover to the rear, back to the front and up. Repeated a second time and stopped part way into the third pass. I don't believe it goes away, but I'll see what it sounds like after it's good and warmed up (another video later tonight).
Temp is about 2C, car was off for several hours (so maybe not stone cold), oil is Amsoil 5W40 EFM. Note the noise at the rear sounds like an exhaust leak (well that's what I've come to know that sound as) and the front is more clattering. Definitely different front to rear.
BMW X5 2004 4.4 185000km Idle 3 - YouTube
Video is fresh, so youtube may have to edit or do things to it. I'll keep posting progress and findings.
Cheers.