Even if you have an old banger no one wants bird shit in their car! But yes, if you've got a fabric interior like me, it probably doesn't wipe away as easily.

Like CCF said, it's probably all about where you live, if I lived in one of those picturesque villages in the country, maybe I'd be more laid back about home/car security, but I still think leaving your front door or car unlocked is bloody daft! (In my humble opinion )