Dude! Are you serious??? Who the hell does that? Someone holding a grudge? If it were me I wouldve jumped in the line and given chase! Believe me it works! Good you got the plates though! If you havent already ring the AFP and report it. Tell them you were struck by a projectile thrown/shot from a moving vehicle. Even if its an egg, its actually a crime you can be charged with. (yes I have had experience with a similar thing, long story)