Opel Automobile Owner's Manual page 73

Automatic wiping with rain sensor
P = automatic wiping with rain
sensor
The rain sensor detects the amount of
water on the windscreen and
automatically regulates the frequency
of the windscreen wiper.
Adjustable sensitivity of the rain
sensor
Turn the adjuster wheel to adjust the
sensitivity:
low = turn adjuster wheel
sensitivity downwards
high = turn adjuster wheel
sensitivity upwards
Instruments and controls
Keep the sensor free from dust, dirt
and ice.
Windscreen washer
73