the dealer installed factory alarm only has a 'glass breakage' sensor, NO motion or toher 'physical' sensors and there's nothing they could have really done wrong install it, the LED, Glass Sensor, Alarm Horn, COntro; Unit and a few connections and they're finished EXCEPT for setting the DIP switches
which give you some minor choices but it actually sounds as though it's working as sold to you.
Stop by the dealer and let them check it real quick
if you nice it might [ought to] be free!!...........jeffb.