Is it a crime to touch someone's car?

Question

I saw a dirty SLK in the office parking lot. I decided to put "Wash me" on it using my finger on its windshield. As I was putting it, the guy who owned the car came and start shouting at me. He said, I can go to jail for this. I kinda got concerned that if you are touching someone's car, is that a crime? Or lets put it this way, does writing on someone's windshield using existing dirt, is that a crime?

Answer 1

If, and a very unlikely if, you were sued or arrested then you could argue that the vehicle was bringing down the tone of the office car park and it looks bad for business and you were justified in bringing it to the attention of the vehicle owner.