1996 Buick Regal Owner's Manual - Page 108

Astroroof (Option) Your astroroof includes a sliding glass panel and a sliding sunshade. The switch works only when the ignition is on. To open the glass panel and sunshade, press the rear of the switch. Let go of the switch to stop the panel in any position. Press the front of the switch to close the glass panel. The sunshade can only be closed by hand. To open the rear vent, press the front of the switch when the astroroof is closed. Open the sunshade by hand. Press the rear of the switch to close the vent. The astroroof glass panel cannot be opened or closed if your vehicle has an electrical failure. 2-42