CAR COVERS ?

They do make lightweight car covers specifically to keep the dust off garaged cars. I recommend the custom fit ones which stay on better and are less bulky when removed.

As for the last comment, you really cannot keep a car cover on a car stored outside year round. If you leave a wet cover on a car, it will ruin the paint, as noted. Even a "waterproof" cover will allow moisture to condense on the car under the cover, promoting rust. The cover is fine to protect against sun, leaves, dust and bird droppings, but the car is better off uncovered in rain and even snow. One partial solution is to erect a cheap driveway canopy (about $120 from Harbor Freight) and use a water-resistant car cover underneath it. That way it doesn't get soaked.