I put my top down when the warm weather breaks and put it back up before it gets below 60 out at the end of the season.

As long as it is warm out when it goes back up the wrinkles seem to go away after the first few weeks of winter storage.

I think that leaving it down for the summer months actually helps it last longer since it isn't always being folded. I also make sure the rear plastic window is clean an free of dust so it won't scratch while it's folded and I place a microfiber towel where the window folds onto itself. After 7 seasons it is still crystal clear as you can see in the photos.