KCZ

I've used Weathershield covers on my cars for winter storage for a long time, and I've had no problems with either my paint or the covers. One cover got sprayed with ? coolant or oil or something while the car was in storage, and while the cover was left stained, the car was completely protected.

Paint damage usually isn't due to the cover material itself, it's due to dirt trapped between the car and the cover, which acts like sandpaper when the cover is tugged on. If I were going to replace a cover on an unwashed car on a daily basis, I'd use a loose-fitting cover like a non-custom Budge so I wasn't grinding the dirt into the paint every day. All largely theoretical and YMMV.