Buick 2004 Park Avenue Owner's Manual page 46

Lower Anchorages and Top Tethers
for Children (LATCH System)
Your vehicle has the LATCH system. You will find
anchors (A) for all three rear seating positions.
This system, designed to make installation of child
restraints easier, does not use the vehicle's safety belts.
Instead, it uses vehicle anchors (A, B) and child
restraint attachments to secure the restraints. Some
restraints also use another vehicle anchor to secure a
top tether strap (C).
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