How could you best keep unauthorized persons from using a mobile station in your car?

As the licensed operator, you are responsible for preventing unauthorized transmissions from your station. In a vehicle, anyone sitting in the cab might easily have access to the radio equipment. Simply turning the power off or changing the frequency is insufficient, as an unauthorized user can easily turn the radio back on or tune it to a new channel. By physically removing the microphone and taking it with you or locking it away, you eliminate the primary means of initiating a voice transmission. This is widely recognized as the most effective and practical method to secure a mobile radio setup from curious passengers or unauthorized individuals.