Hi Dennis
Not sure how well it's "rated" but I got a cover for my '65 coupe. It is the "Dustop" from California Car Cover Co
http://www.calcarcover.com/how_to_select.aspx
My car is always garage kept so I only needed a cover designed for indoor use only to mainly keep the dust off (and scratches and pawprints if the cats sneak outside into the garage like they try to do!). So far it done a good job of keeping the dust off although I've only had it for about 2 weeks now. It's very soft and from the feel of it I'm not worried about it scratching the paint. I hope this helps