Does anybody know what causes the howling noise at high speed with the WRX and how to get rid of it? (not that I drive that fast ;) ) I'm guessing it is the aerodynamics of the mirrors. Is there a way to stop it other than replacing the mirrors (if that's what it is) or using duct tape?

I got the car going fast enough to get the howling noise on my way home from UCKK on Tuesday night and was curious.

I think you are right. I have same problem and it ussually comes from rt side mirror.

i'm not sure about u guys but for me it mostly on elevated areas..
on the same highway going down i went past 125 and no noise at all..but on the way back going on a slight incline at 105-110 the right side mirror seems to howl... i don't know what the problem is but i think it either the mirror or the glass...since we don't have edge guards like other cars