1995 GMC Sonoma Owner's Manual - Page 79

Sliding Rear Window Your vehicle may have a sliding rear window Squeeze the latch in the center of the window and slide the glass to open it. When you close the window. be sure the latch catches. Swing-Out Windows (Extended Cab) To open a rear swing-out window, pull the latch toward the front of the vehicle and then push the latch out and rearward. When you close the window, be sure the latch catches. Horn To sound the horn, press anywhere on the pad on the steering wheel. 2-33