Fight it. Your mph is short not long so under is the answer on that. The cop didn't state his probable cause to you and that is an infraction of civil code. "The reason why I pulled you over"...yada yada... you know what I mean. Also, on radar it does not detect what passes through it. It sends a signal to your car bounces off and returns to the radar. The amount of time it takes for that to happens determines how fast you are going. Good luck!!!