I could be a bit cynical when it comes to car covers, but finding one that checks every box on your wishlist would be like finding bigfoot. Unless your car is perfectly clean with no dust or dirt the car cover will get dirty and eventually scratch your paint. If you don't store it in a dust/dirt proof environment when it's not on the car, it will get dirty and eventually scratch your paint. If you don't store the car where it will be out of wind, stuff will blow under it and it will get dirty and eventually scratch your paint. If you just want to keep bird poop and tree sap off, your best bet would be something like a single use
Car Condom style cover. Other than that self healing PPF would do a better job at protection IMO (not to mention we do a lot more damage on the trails anyway)