[PaulDexler]

I have used car covers for years. I agree that some sort of locking system is necessary, because I had two stolen from my old Mercedes. I used to use canvas, but now the new materials are so much lighter that they are much easier to put on or take off. Be careful of wind. Where I live, I get a 20 mph breeze down a canyon every afternoon, so I can't put on or take off the cover between 4 and 8 pm. I also tend not to keep it on when it rains, I'd rather wipe down the car than have to clean the cover. Otherwise, two beetles, three Karmann Ghias, three Mercedes and two Alfa Romeos later, I use the cover whenever I can. It's better on the exterior, and much better for the interior.
Paul