Ionizer with fine dust sensor incl. visualization in the center display and auto recirculation. The ionizer improves the air quality in the air flow. To achieve this, the air from the automatic climate control system is passed through an ionizer before it flows into the vehicle interior. This reduces germs and other pollutants in the air. This improves the air quality inside the vehicle, which can noticeably increase well-being. The fine dust sensor measures the level of fine dust in the ambient air drawn in and in the vehicle interior. If a limit value is exceeded, the air conditioning system switches to recirculated air. The multiple flow through the fine dust filter in recirculation mode results in an effective reduction of fine dust in the passenger compartment