I know my bro alexmish had issues with the doors not closing/not locking/not registering completely. Bro -- chime in.

Definitely bring this to dealer's attention. Obviously, there is a good chance the work log will say "unable to replicate", but at least you'll have something in writing for the next time it happens. Perhaps go straight to the service manager, grab him for a walk to the car on a cold morning and let him see/listen.

i recall having a whining/flapping noise coming out of my vents on my E53.. really difficult to replicate especially since it would sometimes go away or just unheard due to highway/music noise. I did notice it was louder on colder mornings than other days. So I took the car to the service at 6am, turned it off, waited till they opened at 7 and had the service manager walk to the car with me before ANYONE touched it. he confirmed the strange sounds and had to action the problem.

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2011 X5 3.5D - Platinum Gray / Black Leather / Dark Bamboo, Sports w/ 20's, Adaptive Drive, Comfort Seats, Cold Weather, Premium, Sound, Rear Climate, Technology, Comfort Access, Auto High Beams, Heated Rear Seats, Running Boards, Roof Rails w/Rola Crossbars, Space-saver Tire, Moonroof visor, P/Q Brake Pads, Cargo Mat, Weathertech All Weather Mats, Draw-Tite Hitch.

2010 X5 4.8i - Lemon'd 12/2010.
2006 X5 4.4i - Sold 11/2009.
2004 X5 4.4i - Stolen 8/2005. R.I.P.