I recently bought an 07 Forester and the wind noise from the drivers side door was driving me nuts. I had inserted a strip of 3/8" self adhesive foam strip inside the door seal to tighten it up a bit against the door but there was no noticeable change. I taped the entire door and window seam, took a test drive and found the noise to still be there so I assumed it was noisy airflow over and around the mirror and that I would just have to live with it.
After reading this thread I removed my mirror, pinched the pillar track so the two sides of the seal touch, filled the hole where the mirror control wires pass through with foam and the noise is gone. Thanks for the great advice guys!