I have the PITA style with the bungie cord at the bottom. There is a new style I've seen that the perimeter that makes contact with the tire tread is held on by a metal spring band. You open the band to spread it, then mount it over the tire, then let go. The tension then causes the cover to envelope the tire as needed.
I believe the brand is California Car Covers (look for California Tire Covers). They average $10 per cover MORE but not having to mess with the bungie cord should save lots of time. There might be other brands, too. Not sure how to handle their theft or if this style is stolen more often, but you should gain convenience.
ON EDIT: I found this website. The covers run from $40 to $60 depending on size and fabic. If I understand the description these have the metal band that you spread apart, then mount over the tire tread, then release it to fasten it snugly. I know nothing about its performance, like how long they last or how well they stay on, but they certainly seem better to put on than the bungie version.
ON 2nd EDIT: A better search found these:
http://www.anythingrv.com/staticpage...ing_TireSavers
I guess there's more solution. The largest of this type is $48 per pair.