Recently, I was on my way to a wedding and didn't have the right clothes on and no where to stop, so we stopped the car and I climbed into the back seat to change my clothes. It was hot so I turned on the AC and amazingly, the REAR AC turned on. Yes the rear AC. I was amazed. Perhaps it detected my phone or perhaps there is a sensor, I don't know. When I was dressed I entered the car into the driver's seat, turned off the AC and on again and the rear AC didn't turn on so it detected me somehow. If there are any more undocumented amazing features I would like to know? Like how to quickly re-arrange my favorites list or how to increase or decrease the fan speed simply like the Model S.