DB9 Volante whistle or whine from air side mirrors?

[chriscmore]

Since getting a full PPF wrap on the car, I've noticed a high-pitched whistle sound in my '11 DB9 Volante, which is coming from the side view mirrors at speeds over 60mph, obviously worse with the top open. Thinking the trim spacing was changed with the PPF, I've tried taping over the A-pillar seam, and the seam around the bottom of the side mirrors, to no improvement. I seem to recall someone narrowing down a source of wind noise or whistle in this area but the searches are not showing up for me. Folding the mirrors in at speed kills the whistle noise. Also changing the airflow by putting my hand in between disrupts the sound. Both aren't desirable solutions, but point to the general source. I'm hoping someone has fixed this with an acceptable long term solution. Has anyone else had this and tracked down which feature causes it?