I hate to say but after visiting a Subaru dealership over the weekend there actually does not appear to be a way to turn them. I had gone through the whole menu system and could not finding it. Sadly the Settings > Vehicle > approach settings are only for internal and headlights. I still tried turning it to off for both listed settings but it did nothing for the mirrors. I had the salesmen do some research into and even called Subaru corporate but neither were able to find anyway to disable it. Its a bummer but not a huge loss to go with the standard mirrors.