Rear Ventilation,

Purpose
The air flowing through the vehicle passenger compartment exits the vehicle through the rear vents.

Function
Louver-type flaps installed in the rear vents open as a result of the pressure of the air flowing through the vehicle allowing it to escape.
If a vacuum is present in the vehicle, such as can occur when driving with the windows or sliding roof open, the flaps close automatically by the force of gravity preventing exhaust gas, dust and moisture from being aspirated.