http://www.bbc.co.uk/crime/law/powersofarrest.shtml (Scroll to bottom)

In the uk the general public have the right to place people under a citizens arrest, providing they have witnessed them commit a criminal act.

Myself, I arrested 3 blokes after being assaulted by them. Then got the police involved whilst I held them on the floor, as opposed to transporting them myself to the station.

Its a certain possibility for you to encounter (not sure on laws in the USA but would have thought the capacity should be there) and if I had someone such as yourself damaging my car you can expect to be confronted with "reasonable force" and brought to justice over your actions.