Opel Automobile Owner's Manual page 176

176 Service and maintenance
performed by a workshop within one
week or 500 km (300 miles)
(whichever occurs first).
Display of remaining distance:
1. Switch off ignition.
2. Briefly press the trip odometer
reset button. The odometer
reading is shown.
3. Press and hold the reset button for
approx. 2 seconds. InSP and the
remaining distance are displayed.