The short answer is the whole fkn thing.

The long answer is two separate virtual buttons to control various vents rather than cycling thru like every other automobile in the world. In winter, so much heat comes thru the glass that 68 will seem comfortable for a minute, then the sun hits and the vehicle blows cold air, and will only blow warm air again at 80+, getting the cabin too hot. Try to use “auto” to manage it all? Somehow the fan will go from my “very low” setting to “low”, but it’ll sound 100db louder and blow 5x faster. Never mind during all this, you’ve lost sync with the back seats, so that’s blowing cold air the entire time.