I have the MaxAirII cover on my vent and a AC cover. I also use a Adco Cover for the TT and tire covers as well to protect the tire from the elements and UV rays during storage. People ask me if it is worth it....from my experience, yes. I spent alot of money on our TT and I plan on keeping it for a long time.
2012 Jayco Jayfeather X213
2004 Dodge Ram 1500 Laramie Quad Cab 4x4