It's happened several times now. Every six months or so I will be driving along and I hear the REAR fans turned on and there is hot air blowing into the cabin. Yeah, the REAR heater turned itself on again. The only way to shut it off is to go to the panel on the front, turn the REAR CONTROL all the way HIGH and then back off again. That fixes it every time. My rear control panel no longer works in the rear, either. It only has high fan, and will not switch between heat and air any longer. So if I want air in the back, I have to control it in front.