I know I can't be the first, but I must admit, I was a bit baffled... This weekend we made a 1.5 Hour Trip to Rocky Bayou Campground in Niceville, FL. When we departed, both vent covers were present and accounted for; When we arrived, the one up front had gone AWOL. I installed both of these less than a year ago, and used a ludicrous amount of sealant, as well as quite a few panhead screws around the perimeter. My only guess is my spirited passing of a slowpoke along the way proved that 85 MPH is more than they can take. Guess I'll be installing a new one this week.
Oh, by the way, by cover I mean the Camco covers, not the vent lid itself.