GMC 2007 Canyon - Manual (Page 151)

Rear Storage Area
If your vehicle is an extended cab model, it might
have storage compartments under the rear seats.
To access the storage compartments, lift the
cushion on the bottom of the rear seats. This
exposes the storage boxes under the seat.
To open a storage box, unhook the bottom and lift
the two latches on each side of the storage box.
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