Cops love Mopars.

I have been driving my Dart around my town with open headers for about 2 years now. Never had a problem with it until a few days ago I pull up to a grocery store and a motorcycle cop is sitting in the parking lot. I drove by with everyone in the parking lot giving me thumbs up and stares then the cop decides to be a jerk. He pulls in front of me so I stop and he begins asking me what show I am going to so I said non I am driving to work. He tries to tell me that since I have historical tags on my car that I can't drive it unless going to a show. I actually had a off duty cop in the car with me and he says "you have no clue what your talking about. Have a nice day" and told me to leave so i took off and nothing happened.