I have had this enoying whistling sound (Not the Super Charger) coming from the passanger side of my CAB above 60 mph. Yesterday had I my son ride with me and it is coming from the opening on the passange side mirror. If he puts his hand in front of the mirror the whistling sound goes away.

Any sugestions? I dont have the same issue on the drivers side mirror.

 

Take it to the dealer this is a known problem with the mirrors. Mine was replaced under warranty.