people who have to mess with other peoples cars

It makes me really mad when somebody just has to mess with my car when im not around. Like when they put stickers and shit on my windows or when they throw there lunch on my windshield while I am  driving. What really pisses me off though is that its always the people whos parents gave them a car and they didnt have to buy it with there own money so they dont give a fuck about messing with you car.