I have the reverse sensing system & the alarm. So far I can`t get it to work & after locking the car with the top down with the button on the key fob, I can still reach inside the car & open the door with nothing happening. Maybe its time for me to read the OM.
Yes, the owner's manual explains that the motion sensor is automatically disabled when the top is down to prevent false alarms from things falling into the open car. The rest of the alarm is still active. You can put the top up but leave the windows down in order to test the motion sensor.