Well, if if didn't start automatically while plugged into the gps mount and is now starting automatically when you have it plugged into the side of the camera, I would assume you have the "older mount". Every time you restart your car, the A129 should turn on (you'll hear a chime or two when it does so). It will automatically go into parking mode when you turn the car off "unless you turn the camera off" before turning your car off or after turning your car off. - - This is what I do when I'm at home as I don't want the dash cam running at home.
Btw, the attachment has the serial #'s of "new mounts" which was provided by Capture Your Action. - - I assume I have the older mount and it's a moot point anyway as I have the A129 mount butting up to my rear view mirror mount; I could not plug a wire into it, unless I repositioned my dash cam mount. nbd; I'm finding I almost never remove the dash cam anymore...