I've discovered, some 18 months after buying the car, that the rear-hatch doesn't lock. using either the key, remote, or inside-lock button. One can always open the hatch, and when the alarm is armed, this'll trip off the bleeping horn.
Except sometimes. ...Sometimes I do find the hatch is locked on returning to the car.
Which sorta implies to me, that the lock cylinder itself is not broken, but that there might be a 'protocol' with the remote, that I haven't caught on to. or perhaps something weird, like the remote/power-lock subsystem, being out-of-sync w/ the hatch's locked/unlocked state ....
otoh, I cannot force the hatch key all the the way clockwise (presumably locking it) and still remove it. (I tried 2 keys)
I've googled a bit, and hadn't found any references to similar problems; has anyone else seen this?