We have a Calmark cover for our Escape
. We snug the two straps. They keep the winds from flapping the cover. The draw string underneath: again-snug.
By snug, I mean, cinch them up to where they're tight, but you can fasten and undo the snaps without having to re-adjust each time you put it on.
We also have a 3/16 nylon rope underneath that cris-crosses between many of the grommets. We connect with a bunch of snap rings (see your dollar type store for the deals!). We tehn just draw it tight from one end or the other.
This also keeps the wind from moving the cover.
We've had the 5 years, in the So.Calif. Santa Ana winds, and there are no scuffs on the trailer finish. The cover is in great shape, even with SoCal sun.
Edit: we don't have the cover over the front storage and propane
. I used some Krylon Fusion plastic compatible paint
on the cover when new, to provide UV protection. (I also used the Fusion paint
on several of the plastic vent covers, and on the top half of the A/C cover on the roof, again, for UV protection.)