the windshield defroster is a lever in the middle of the upper two vents (no kidding).
the sliders, idk, i can't tell any difference in airflow anywhere regardless of where i put them, and the fan speed.
also, the tripmeter on the 944 is a joke to. its literally a fin in one of the vents, you push it to zero the trip.
its like they ****ed it all up on purpose.