Auto HVAC works perfectly well in most homes, and nobody wants to control temperature by directly turning on and off a furnace. That being said, auto control is

Auto HVAC works perfectly well in most homes, and nobody wants to control temperature by directly turning on and off a furnace. That being said, auto control is not such a great convenience that many people upgrade old-school radiators to have thermostats. But unlike a home, when a car is constantly changing direction, and speed, and sun is in your face or out of your face at times, perhaps you have heated seats that you've turned on, control based on a single temperature will always have difficulty making you feel comfortable. Better to control things directly.