These plastic handles are notorious for drying out and then breaking at the worst possible time. On the Gen2/2.5 Montero it is not as big of a problem because there is a handle on the inside of the door as well. But on the Gen3, if this handle breaks then you have to take apart the rear door trim from the inside and manually pull on the lock rod to unlock the door. 

 

We recommend cleaning the door lock actuator while you're in there because a dirty/gummed up actuator will put undo strain on this handle causing it to be harder to actuate and fail prematurely.