[Derek Lecours]

Hi George,

You have to remember that any cover you put on will hold dust on it. As you roll it or pull it off, you will contaminate the inner surface of the cover with that same dust your trying to keep off the car. Car covers are used everywhere here in North America, but usually to protect from the sun and or light dust while in the garage. My A6 is garaged and also under cover because I never take it out enough and don't want to wash it before I do. If you Google car covers, there are endless of every quality to choose from, and it can be more of a problem in dirty areas as Keith was saying.
Portable garages is a huge business here in Canada and almost everybody uses them for winter snow protection when they don't have a garage. But I'm not sure if that's what you want. Let me know exactly what you want and I'll work on it for you.

Cheers, Derek