I can almost bet you its not the tow mirrors. My Crewmax with the tow mirrors is fairly queit. However this 2WD 07 Tundra w/the smaller mirrors the dealer currently has me in has noticibly more wind noise than my Crewmax. You can really hear the wind noise beat around the windshield pillars. I would be disappointed if this was my truck, its pretty bad on a gusty day.
My tow mirrors have a considerable amount of wind noise. I had an F150 with smaller mirrors and I now have the CrewMax. The wind noise is definately louder. Its not enough for it to be an issue however.
If you have the stereo on at pretty much any volume its not noticeable.
Then again, I drive mostly city miles. I haven't gone on a long trip where my speeds get up in to the 60's, 70's, 80's for an extended period of time.
I came out of the Super Duty F 250. I am hearing a funny noise in my DC with tow mirrors at highway speeds.............Wait I think that is the radio. It is the first time I have heard the radio at highway speed in 7 years. Got to love the tight fit and finish of this new Tundra.