I am using in-channel wind deflectors and I am very happy with them. They help a lot against the rain if you want to keep your windows open, but they useless against the wind. Why somebody called them wind deflectors when they should be rain deflectors??:8:
I like my in-channel deflectors. I can have the windows about half-open while driving in the rain and only a few drops find thier way in.
The rear window deflectors, however, are suffering from not staying in place. MacNeil Automotive (the folks that make and sell the WeatherTech deflectors) has been very good about sending me a replacement visor for the one that came out of the rear window while driving, and a fresh roll of adhesive tape to redo both rear windows.