2012 GMC Canyon Owner's Manual - Page 106

4-2 Storage Rear Storage Extended cab models might have storage compartments under the rear seats. To open a storage box, unhook the bottom and lift the latches on each side of the storage box. Lift the lid from the center area to access the storage box. To access the storage compartments, lift the cushion on the bottom of the rear seats. This exposes the storage boxes under the seat.