2010 Buick Lucerne Owner's Manual - Page 122

Rear Seat Pass‐Through Your vehicle has a small door in the rear seat. This door allows you to access the trunk from inside the vehicle. The rear seat armrest must be down for the pass-through door to open. To release the pass-through door, move the release lever up. To close the door, raise it and push it until it latches. Windows { WARNING: Leaving children, helpless adults, or pets in a vehicle with the windows closed is dangerous. They can be overcome by the extreme heat and suffer permanent injuries or even death from heat stroke. Never leave a child, a helpless adult, or a pet alone in a vehicle, especially with the windows closed in warm or hot weather. 3-14