Car cover question

just a thought if your is in a not so safe area in the open someone could throw a lit ciggarette at it or set it on fire just to be an a--, also if your not driving your car that often then a cover is a good idea, alot of wear and tear also comes from taking it on and off, i live on a corner with a high traffic street so the dust and wind is bad here and that makes it hard on a cover too. i have mine tied with rope and heavy rubber chocks across the top to keep it secured on the car