In some states, if you have snow or ice on your roof and drive, you're in trouble. You are supposed to remove all the snow and ice from your rooftop because it dislodges and falls onto traffic or the road behind you.
They should make snow car condoms for various models. Cover the entire thing.
And for the opening on the top…why didn't they cinch it or magnetize it? The snow will fall on that "lip" and weigh it down to allow more snow to fall on the windshield.
I think this is for Hollywood snow and not real, in the middle of the storm, snow. Snow isn't fluffy all the time when it falls. It can be, and oftentimes is, heavy, wet, icy, stingingly hard. If you had three or four inches of heavy wet snow on top of this tablecloth, you would need another car to hook into it and pull it off.
It might be good for bird poop, pollen, light fluffy fairy snow, leaves and needles, or just to hide behind when parking on lover's lane...