I only cover it for it's Winter storage. So, I'll cover around Oct and it stays on until May. In between time, I don't cover.
The cover in my pic on the previous page, at that time, was around 10 years old. I retired it this year (2 years later) and have a brand new ADCO AquaShed Designer Series cover waiting to go on come Oct.. Cost me $175 for the 20' size.. I don't have that big of a trailer.. :)
If it was physically possible to have a covered car port for mine, I'd have it.. But, the logistics of how I have to park it won't work, so this is my best solution.
Good luck!
Mitch