I have the 320d F30 in South Africa. We have a plant here at Rosslyn - but I also experience the exact same problems with wind noise. At speeds above 90 kph, a whistling noise enters the cabin from all the doors, mainly the front ones. So I think it's a design issue rather than an assembly issue, since this seems to happen all over the world.
I've had mine back to several dealers multiple times - next week it's going in for the 5th time in 4 months
So far they've done the following, with no difference to the noise levels:
- Refitted Windshield
- Replaced all the door seal rubbers
- Realigned all the doors (and in the process messed up the one to the extend that it needs to be slammed extremely hard to close)
The tech from BMW also said it is because of the side mirrors' design not allowing air to flow off of it, but rather routing it over the windows, causing more wind noise. What a pity. BMW should seriously recall this issue - it's not very German like...