cool, for me it was definitely the door lock actuator. They replaced it and it went away.

Keep in mind the ECU does a self-check/calibration on basically all the engine servos (throttle bodies and VVEL actuators) about 2-3 seconds after you shut the engine down. You'll hear the Pulse Width Modulation frequency (the mid-frequency digital sound you can hear from the engine always while running), and some clicking/clunking as it runs them through their full range, and then quiet. I LOVE THIS PROCEDURE'S SOUND!!

Cool I'll check out the door lock actuator.. I also have the same issue, most of the time I turn off the car it makes that noise. Also before I turn off the car, I unlock the doors and that noise is present. I have an oil change comming up, so ill bring it up to them. Thanks.