Hello Kalex, I put up our bed flys up every time including overnight roadside stops for all the reasons mentioned earlier. However the main reason is they stop bird poop and tree sap getting on the canvas. Best way to devalue your camper is stained canvas. I learnt my lesson when I parked under a tree in Leonora a few years ago with my previous camper not realising it was the cockatoo's night toilet. What a mess we awoke to, never cleaned up. Since that event my Jayco has been crapped on by any number of birds big and small and you should see the mess the fruit bats can make in one night. And I haven't even started on sap. The plastic bed end flys are a good investment IMO