When I look at the clearance between the door frame and the mirrors when folded, I do wonder how the hell the deflectors would fit without being crunched when the mirrors are folded up. There is almost no gap there to accomodate the lippage of the wind deflector.
Why anyone would want these is beyond me. They belong firmly on an old Austin Maestro with wooden bead seat covers.
The golden rule of car ventilation in the summer is windows down to 30mph, then put the aircon on for speeds above that (as the aerodynamic losses of having the window open are greater than the power required by the A/C unit above 30-35mph, and wind noise is really noticeable above that speed)