Had a guy tailgating me once, years ago before we called it road rage. I did what I normally do, slow down. When he finally pulled past me, I looked over and he was holding a little POS .25 auto in his hand up against the back of his passenger seat, so I could see it and be intimidated. So I sped up, and held up my .45 for him to see, and just grined at him. I guess that goes to show, you have to be careful who you threaten.