A special sensor system in the Phaeton reduces misting-up of the windows and enhances climatic comfort by managing the interior humidity. From the data delivered by the humidity and temperature sensor in the base of the interior mirror, the Climatronic control unit calculates the dew point temperature of the air - that is, the temperature at which the air humidity would condense. Also, the humidity in the air in the vehicle interior is set to a level which is undamaging to the skin and to the nasal membranes. An infrared sensor remotely measures the radiated heat on the windscreen, and thus the window temperature. To prevent the windows from misting-up, the Phaeton's automatic air conditioning system regulates the air humidity accordingly.