When the Model X is either parked or driving, the rear air conditioning (which is third row seat vents and second door door vents) does not turn on unless there is someone sitting in one of the second row seats. Since I routinely carry my dog in the hatchback area with the third row seats flipped down, this came as quite the rude shock when I accidentally discovered this today. No wonder my dog doesn't want to ride there, she was being cooked with only the little amount of air coming from the front vents not even reaching her. I've just asked Tesla if there is some way to force the rear HVAC to stay on. I'm quite pissed off about this, this is a real safety hazard in hot sunny climates.