I would scream back at them, pull out the Uzi that I just happen to be carrying with me, and fire a shot into the air as a warning. If you try to call 911, he'll see you doing it and try kill you. So I wouldn't do that until he leaves. If he decides to stay, I will summon the god of war and fire, Mars and Vulcan. Jupiter can come if he wants to also. If his car is impenetrable by any force, I'll just have to bring the world to an end right then and there. And then I'll hope that Jupiter was happy with my decision.