Automatic start of heated seats can be set to be activated/deactivated when the driver gets into the vehicle.1 With automatic start activated, heating will be turned on at an ambient temperature of 10 °C (50 °F) or lower.
Tap the temperature button in the middle at the bottom of the center display to open Climate view.
Press 
Choose a setting under Auto driver seat heat and Auto passenger seat heat to activate/deactivate automatic start of heated driver's and passenger's seat.