sixto,

It depends on the chassis, the 124 sensor is down low and the air is drawn through the grill at the rear view mirror down to the sensor.

The late 123 chassis, as was the original question in this thread, the sensor is indeed behind the grill, but the air is drawn over the sensor by the draft drawn through the foam tube that disintegrates over time.

I don't know where the sensor is located on the 126 or 140 chassis. I'm a poor boy and have to drive the little cars.

Regardless of whether the sesnsor is five feet away or right at the grill, air must be drawn through the grill someway.

Good luck,