Originally Posted by Frogman
That's an excellent idea!
I looked through the FEM_BODY values and found the likely setting. It's currently set to open the mirrors at 40 km/h, or 25 mph.
I'll give it a try when I get a chance and report the results here. Thanks!
Well, I coded the mirrors so that they can be folded in or out at any speed. I took a drive on a smooth, flat 55mph road with no traffic on it.
With the mirrors out at 55 mph, I get a definite wooshing / buffeting sound from the area of the A-pillar. It's really hard to isolate exactly where it's coming from, but it is not road / tire noise.
Unfortunately, when I fold the mirrors in at 55 mph, the sound gets worse! It's louder with a slightly higher pitch and a more complex sounding wooshing sound. Folding the mirrors back out returns the sound to normal.
I guess it just proves that you actually can make the mirrors aerodynamically worse if you try hard enough.
At least I'm now pretty sure it is the mirrors are making the noise and not the door seals, side windows, or the windshield. If BMW actually does have new mirror caps and/or assemblies to address the wind noise, maybe there is hope that they noise level can be reduced.
Another thought: Anyone brave enough to completely remove the entire mirror assembly and see if that stops the noise? (Not me!)