2002 Buick Rendezvous Owner's Manual - Page 228

Rear Window Defogger Press the REAR button (the indicator light will glow) to warm the defogger grid on the rear window. The engine must be running for the defogger grid to warm up. The system will turn off automatically after about 10 minutes of use. If you turn it on again, the defogger will operate for about five minutes. You can also turn the defogger off by turning the ignition to OFF or by pressing the button again. The indicator light will turn off. Manual System If your vehicle has heated outside rearview mirrors, the outside mirrors will also defrost when you press this button. Do not attach a temporary vehicle license across the defogger grid on the rear window. NOTICE: Don't use a razor blade or something else sharp on the inside of the rear window. If you do, you could cut or damage the warming grid, and the repairs wouldn't be covered by your warranty. Automatic System 3-9