1) Keep firearms out of sight.
2) Do not volunteer any information.
3) Obey all laws.
4) Have no drugs or other contraband in the vehicle.
5) If you are asked to give permission to search the vehicle, politely decline to give permission. Ask for an attorney. Have an attorney, and his/her business card handy.
6) Always be polite, friendly, and cooperative.
7) When pulling over, signal, pull to a safe area, turn off vehicle, turn on inside light, have your hands on the steering wheel, palms up, look the Officer in the eye.
8) His gun is much handier than yours, act accordingly.
9) (Optional) Only roll the window down a couple inches, as it is more difficult to drag you through it that way.