Buick 2007 Terraza Owner's Manual page 68

2. If the child restraint manufacturer recommends
that the top tether be attached, attach and
tighten the top tether to the top tether anchor,
if equipped. Refer to the child restraint
instructions and the following steps:
2.1. Find the top tether anchor.
2.2. Route, attach, and tighten the top tether
according to your child restraint
instructions and the following
instructions:
68
If the position you are
using does not have a
head restraint and
you are using a single
tether, route the
tether over the
seatback.
If the position you are
using does not have a
head restraint and
you are using a dual
tether, route the
tether over the
seatback.
If the position you are
using has an adjustable
head restraint and
you are using a dual
tether, route the
tether around the head
restraint.