All of the warping complaints I've read about had to do with leaving the Slingshade panels up in strong sunlight and the panels evidently warping from the heat and then not closing properly. Leaving the panels closed seems to avoid this.i have never had a problem with my Slingshade. I also have a rear view mirror mounted to the front of the shade.
I fabricated a rear view mirror on my stock sling shade from an Arlen Ness chrome Harley mirror mounted to a billet aluminum plate powder coated the same color as the roof. It is held on with 3m automotive tape so I didn't have to drill holes to mount itI'd love to see how you did that. Do you have any pics?