Pretty sure I know the wind noise you are talking about. I have the same noise but it sounds like it comes from both sides most noticeable on the drivers side because you're closer to it. It's not like the type of noise you get from a leaking seal like when a window is partially cracked or a door isn't full closed. It sounds mores like air turbulence outside of the truck I think it's the sound of the of air passing over the mirrors, it's loud enough to hear inside of the cabin with the radio off and AC down low. The first time I noticed it I was on the freeway with the radio off 75 MPH, I though maybe it was just because it was windy out. But I've noticed that it starts at about 45 mph and gets louder the faster you go even when the air is dead still out. The only other way I could describe it, It's like being in the vehicle whiles its parked and its extremely windy outside and you can hear the wind passing over the vehicle. Is this like the wind noise you're hearing?
I want to try masking the joints of the side mirror with painters tape to see if that helps, just keep sealing cracks and slots until I find the culprit then come up with a more permanent fix once I locate it.