The clicking could be coming from the relay on the door lock control PCB, which is mounted on the drivers door near the front, about midway between the speaker and the mirror. I'm currently going through my door lock system piece by piece because it had become intermittent in operation. I haven't found the source of the problem yet. Might be in that PCB, or it might be in the wiring, perhaps at the door hinge area where it gets flexed with door movements.