Car ownership is a thing of mutual trust. Most people have them and most people leave them parked on drive ways and on streets for prolonged periods of time where they can potentially be vandalised. The key thing is, if you don't want your stuff damaged, don't damage other people's stuff. Hopefully karma will act upon this and they culprits will have something precious of theirs damaged in some way as the universe seeks to recompense you. The only annoying thing is you'll never actually know. It makes me livid. My poor car is a state due to this. Cigarette burned plastic trim, dented bonnet from idiots running across my car, scuffs from undeclared parking scrapes and damage to paint where cigarettes have been flicked onto the bonnet too. In all, I've given up caring about the appearance of my car until I live somewhere with a driveway and/or garage. When this happens, I'll body shop my car for all little sinks and dents to be sorted, a full respray and then weekly polishing will ensue.