Hi Carlo
Centre vent is really designed to put hot or cold car into the back of the car. It goes over your head and circulates behind you, creating a 'climate' in the car. Not a lot you can do about it. Best solution as Steve says is select face vents and then maybe close the passenger vent (if in the car alone) and max out the drivers RAM vent. Also, in the short term, open the rear side pop out window which will allow more air into the car, the flow through air is limited by the flow rate capacity of the rear vents to evacuate the air. However, if stationary, warm air will start to bleed back into the car through the open window, so keep moving !! 😏