AIR-CONDITIONING is optional in the Astra. The heating/ventilation controls use ergonomically correct rotary knobs placed in the centre console within easy reach of the driver. Unlike some Holden models, passengers can select recirculate mode yet still have control over directional airflow. An air pollen filter is fitted to help keep the interior free of contaminants. A rear window demister is standard and external rear-view mirrors in the CD model are heated for quick demisting in winter.