I have an ongoing battle with Ram over the very poorly designed huge tow mirrors. Ram acknowledged the problem but won't do anything about it.
Meanwhile, there is another big source of wind noise...namely from when the sun roof is opened. Above 30 mph, the roar blocks out the radio and any normal speech. Today I installed an AVS sun roof wind deflector. It easily attaches and looks innocuous. The big surprise came when I drove the truck. Not only was open sun roof wind noise reduced by at least 70%, but the perceived tow mirror wind noise was reduced as well! I don't know how roof wind noise amelioration also reduced side mirror turbulence, but I assure you, it did.
To prove the noise reduction, I took my son along and I drove at a constant 105 mph where the wind noise is so intense, you could name the 'storm wind' outside the truck. I closed my eyes and my son dropped a pin. I could actually hear the pin drop hitting the rug, bounce once and come to rest on his sneaker. Amazing!