Vent Window Operation
Vent windows are one of the things I really miss on newer cars.
Regarding yours, they should neither "lock" in place nor should they flap in the breeze. There should be enough resistance to open them to just where you want them and they should stay there until physically moved.
I know there should be some way to adjust them but I don't know what it is.
Someone here will chime in with a fix for your "swingers".