[Tom W]

I don't think it's a question of "cable stretch" but the top and window can/will get a wrinkle in them from where it folds back. The manual says not to leave it down overnight or longer.

That said, I've left mine down for a few days to no ill effect - it just takes a little longer for the fold line to go away once you put it back up. I also know of guys from the LA area that almost never put theirs up and are happy with it.

Use the cover, it cuts down on the wear from the top flapping in the wind and get a wind-stop, it's a nice addition that cuts down on the back-draft.