Thanks again. That certainly explains it, because I first noticed it as I was driving with the window partially open on the freeway. There is definitely a lower level of airflow between the "off" and the first "on" fan setting as you mentioned.The interior fan runs whenever the ignition is on IGII. The fan switch "Off" position is a fib, the fan jruns at a very slow speed, but it still runs. When the E is moving you''ll get some additional airflow from the air compressed at the bottom of the windshield into the intake vent. Open a window or skylight and drag will suck more air through the vents into the cabin.