Hi, I would suggest you don't use one at all. They can do more damage than leaving them open to the elements. They tend to make the paint 'sweat' and you end up with microblisters. After rain the wind will dry them out. Just give them a good wash and polish before the weather sets in and during if you think it's necessary or you're worried.
Mine is a Cover-zone Monsoon, which is a multi layered waterproof cover.
I think it is a good idea to cover your car when outside over the winter. I did for a few years and the car always looked great in the spring. Yes, it slightly marks the paint, but much less so than freezing water, snow and rain deposits. Just think of the marks as something to polish out of if you're into that sort of thing. With the cover moss didn't grow on the car, the brakes didn't seize and car didn't blow away. The cover also kept the interior of the car much drier than with no cover over a damp winter.
As I've only had one cover I can't compare covers. So I can't 'recommend' as such the one I bought, but I was very happy with it. I got two winters out of it until it really started showing signs of end of life, which was not helped by the cat falling asleep on it and doing that claw scratching thing, although the outer layer was damaged by this, the cover remained intact.
Here's a picture of the cover over the P6.
I put a spray can lid over the aerial mount in the front center of the roof and something over the side light sticky up bits would be recommended to stop holes appearing in the cover.
Hope that helps.