just my two cents
My brother is a car collector (the expensive museum types).
He strongly suggested to me not to put a cover on my car in the garage. His reasoning is that people think the cover will keep things like bicycle handles, skate boards, laundry baskets, etc from denting and scraping the beautiful body underneath.
His recommendation was to keep a "California Duster" handy, and dust it off as needed. Also as the washer and dryer are in my garage, he said to dust it before the laundry otherwise the dust sticks from the moisture and acts like sandpaper when you try to remove it.
His cars look incredible, and so far I'm having good luck with mine as well (although it's definitely not a museum piece).
Just something to think on. YMMV,
Scott