No joke, but I worked at Walmart last summer. If we saw anything anything done to a car, we were instructed to call management who would then call the cops. If we were told by someone/a group that they were going to do anything (against a friend), we were told to tell them they can't do that and they have to leave. If they did do it anyway, we would call management and they would call the cops. You would be in a much "better" position doing it at school. By doing it in a commercial parking lot, you are bringing in another party into a bad situation. If Walmart/an employee were to look the other way or not report it, then something is damaged on the car, they are involved now and you don't want to involve someone like that for the sake of your wallet.
