Legal Question in Criminal Law in Massachusetts

If there is no property damage, and no one was in the car, the odds are nothing will happen.

Although I agree with Attorney Lebensbaum, I can't tell if there was anyone in the car from your description. I have seen a person charged with assault with a dangerous weapon for throwing coffee on someone's desk.

Also, beware of a ridiculous trespass or vandalism complaint which your neighbors could bring to a clerk even if police view it as too petty to address.

Bottom line, don't talk to the police.

You have received good avice above. Do not speak with the police. There could be a charge of vandalism, but it is unlikely that the coffee did any damage. I would think that nothing will happen, ut if it does, speak with a local attorney who practices regularly in whatever court you are charged in.