GMC 2007 Acadia Owner's Manual page 80

Driver Side shown, Passenger Side similar
The seat-mounted side impact airbags for the
driver and right front passenger are in the side of
the seatbacks closest to the door.
80
Driver Side shown, Passenger Side similar
The roof-rail airbags for the driver, right front
passenger, passengers behind the driver and right
front passenger, and the third row outboard
passengers are in the ceiling above the side
windows.