It's the temperature sensor and not anything hands free!
When you dial-up up a set temperature either on your rotary dials or climate control, the sensor checks the cabin temp and opens/closes the valves on the heater matrix/aircon. If you have climate control it works in conjunction with the domed thingy (sunlight sensor) in the top centre of the dash.
If it was a hands-free mike it'd be on the wrong side of the car for left-hand drive and therefore not much use.
When you dial-up up a set temperature either on your rotary dials or climate control, the sensor checks the cabin temp and opens/closes the valves on the heater matrix/aircon. If you have climate control it works in conjunction with the domed thingy (sunlight sensor) in the top centre of the dash.
If it was a hands-free mike it'd be on the wrong side of the car for left-hand drive and therefore not much use.