Stayed put at 140+ today, me thinks it has something to do with how it's installed. The fender can be tensioned in two directions depending how you install it.
The obvious bolt in method would spread the fender out a little, creating downward pressure, I used multiple black aluminum washers to give a squeeze instead of a spread to the fender. My original intent was to avoid scratching the carbon, but, the install may have benefitted it's strength too, I'll snap some close ups tomorrow when it's light out.