I would like to add, with my latest car, I purchased a fair car cover. I kept it on as much as possible, and dang if its not like a garaged car, maybe even cleaner, and its a driveway car (in Phoenix if I may add, which is a huge dust environment). I actually wore out my car cover (thin material, not well made), and purchased a very nice one recently and man, that thing is nice. During heavy rains, it keeps the car dry, and yet somehow this thing breathes. If you can get in the habit of putting on a car cover, its well worth it. Keeps the sun out of the interior, keeps the paint out of the sun, keeps the dust off, etc.
I have a pretty good system of folding the cover up. I am on system two now. I could probably fold a parachute now in record time and do it in seconds. Same with putting the cover on. I loop thing band around the rear plate, unroll accross the top, fold in the mirrors, loop over the nose, and flip down the sides.
Getting one that fits 'perfect' is optimal. If its too tight, it will tear. If its too loose, it will blow off all the time, and that gets dust on it. Always fold the thing where the inside keeps clean, and never let it touch the ground. If its really dirty, you might be able to wash it in cold water, air dry. I washed my first one a few times. You can either roll them up, bunching them in as you roll, or you can fold them in halves, with inside to inside, outside to outside, so they do not get the dust from the outside into the inside surface.
I ended up getting a bigger size for mine then recommended and it was almost a perfect fit. I then bunched up a spot on the nose with a nylon strap and that dang thing covers up everything. The last one before this was super tight and the front bumper showed. I hated that...
Bill