I've been reading this and thought I would say my peace, and to the OP, good thing nothing bad happened to you or you didn't have to use your weapon. All the LEOs I know advise against flipping anyone off. In a driving situation, depending on the cop stopping you, you can be cited for instigation. It doesn't matter what the other guy did, if you get spotted flipping the bird to another driver and stopped that's what can possibly happen. I know I've done some single digit communication in some instances, but I mostly now refrain from it and just curse them vocally in my car. YMMV.