My in the channel visors don't whistle at all. I have used both Weathertech and EGR brands. I prefer the in channel design due to a sleaker profile and easy to remove when you want to.
On a side note: the Weathertech in channel visors will fit with TTT mirrors without modification and the EGR visors will fit with slight trimming on the front leading edge. This applies to a 2002 with TTT mirrors.
My personal choice is Weathertech. Come in clear, smoke and dark. went smoke in the front to match the tint, dark in the rear to match the tint. The nice thing about these is the front's go all the way down in the front to the base of the window vs most which only go down to about the top of the mirror base.
I'm happy. No whistle, less wind noise (I keep telling myself) and I can drive in the mornings with the window open 2" and not get soaked at every stop light/sign. I also like the look or actually the lack of. The only thing I don't like is the fact that the glass does slid on the plastic. You can here the grit sanding away, so far the glass is OK.
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