It does work, but really sucks for those who want to light up a stogie while driving. Having only the windshield open blows the smoke and embers right in your eyes. Same for cigarettes. Ask me how I know.
You need to work on your technique...
Open the drivers windshield to the first "notch" in the brace. Six inches is not required to reverse the airflow and keep the cab cool. When you need (yeah right, like a hole in the head! When you
want) a smoke, crack the driver's door window a bit less than half way, it'll back off the breeze long enough to fire one up, so long as you lean (just a bit, not a lot) to the right, out of th wind. You need a decent lighter, but nothing spectacular, just a regular old Bic that hasn't got too much pocket lint in it to prevent a steady flame). Then SLOWLY close the driver's side window a little at a time, there's a good "sweet spot" probably a couple or three inches down where the windshield breeze is reduced, but the cab is still just barely lightly pressurized. Still a little breezy, but not nearly so much so as with the side window shut completely. You can then use the transfer case shifter hole like a vacuum powered ash tray.
