Anyone use an outside Carcoon to store your 7

[Swikes7]

I have a secure driveway but unfortunately no garage. At the point I get another 7 I would like to keep it protected. I've looked at Classic Additions outdoor car cover which seems very good and gets good reviews. However I'm not sure this will help with corrosion long term and wondered if a Carcoon would be better?

If you have one what size did you get? How easy is it to get the car in and out? How much protection does it offer?

Thanks in advance