Sometimes when I close the rear hatch the car automatically locks itself and the alarm arms (chirps). Other times, the hatch just closes without locking/arming? The key is always in my pocket. What is the variable that makes it lock?

Thanks - too lazy to read the OM...

If your Q is locked and the first door you open is the rear hatch, it will only unlock that door when you grab the handle or press the button on your fob. When you close it, it will lock again. So if it does not chirp when closing, that means the vehicle is unlocked.