1. Insert your car key into the ignition, leaving it in the off position.
2. Depress and hold the M button on your radio.
3. Turn the car key to the on position and turn on the radio with the M button remaining depressed.
4. Write down the serial number that appears on your radios display.
5. Send your BMW serial number to a third party that can retrieve unlock codes such as the BMW Express Code retrieval service (see Resources).