Oldsmobile 2004 Silhouette Owner's Manual page 64

Third Row (50/50)
An anchor bar for a top strap is located at the rear of
the seat cushion for each second and third row outboard
seating position.
1-58
Third Row (Stowable Seat)
The anchor bar for the stowable bench seat is located on
the passenger's side of the crossbar. Use the center
seating position to use the anchor bar properly. If the
convenience center is in the vehicle, you must lift the tray
sill to use the anchor. See Convenience Center on
page 2-58 for more information.
Do not use a child restraint with a top strap in the right
front passenger's position, because there is no place
to anchor the top strap.