2000 Pontiac Bonneville Owner's Manual - Page 170
2000 Pontiac Bonneville Manual
Page 170 highlights
Rear Window Defogger The lines you see on the rear window warm the glass. Press the button to start warming your window. A light will glow in the button while the defogger is working. NOTICE: Do not try to clear frost or other material from the inside of the rear window with a razor blade or anything else that is sharp. This may damage the defogger grid. The repairs wouldn't be covered by your warranty. Ventilation System If your vehicle is equipped with heated mirrors, this button will activate them. After 10 minutes it will turn off by itself, or press the button during the heating cycle to turn it off. If you need additional warming time, push the button again. The system will then operate for five minutes before turning off by itself. If your speed is maintained over 30 mph (48 km/h), the rear defog will not turn off automatically to help keep the rear glass clear. Do not attach a temporary vehicle license, tape or decals across the defogger grid on the rear window. For mild outside temperatures when little heating or cooling is needed, use the panel outlet setting (on the standard system) to direct outside air through your vehicle. Air will flow through the instrument panel outlets. Your vehicle's flow-through ventilation system supplies outside air into the vehicle when it's moving. When the vehicle is not moving, you can get outside air to flow through by selecting any air delivery mode and any fan speed. 3-10