Have used ours for two years in the southwest. When a the wind or a storm comes up we never take it down and have never lost it. Having said that, I can't tell you what the wind speed was or at what angle the winds were hitting the windshield.
We usually install it over the windshield wipers because it's easier to install that way and it provides UV protection to the wipers. If we were worried about the wind, we could install it under the wipers.
Have also installed additional shades on the front two side windows without any problems.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.
