Zombie thread, but THIS is the cover to have.
Waterproof on top, water resistant, BREATHABLE on the sides.
And covered VENTS on top so moisture condensing inside has an escape.
No other cover works NEARLY as well as these.
If they added some bungee-held-closed "windows" that could blow open in a big windstorm, (like certain umbrella designs) it would be a PERFECT cover.