Call the police. At stoplights, leave plenty of room between your vehicle and the one in front of you in case you must pull away quickly. Always keep doors locked and windows rolled up when driving or when parked. Keep valuables in the trunk or in the locked glove compartment. Learn emergency vehicles' signals.
Police lights are red and blue.
Do not stop for flashing white headlights alone. Do not resist in the rare event that a stranger demands your valuables. Your well-being is more important than your belongings. Always use seat belts. It is the law and may save your life in the event of an accident.