Buick Regal Owner's Manual page 102

3-48 Seats and Restraints
If the position you are using
.
does not have a headrest
or head restraint, or the
headrest or head restraint
has been removed, and you
are using a dual tether,
route the tether over the
seatback.
If the position you are using
.
has an adjustable headrest
or head restraint and you
are using a single tether,
route the tether under the
headrest or head restraint
and in between the
headrest or head restraint
posts. See Head Restraints
on page 3 2.
If the position you are using
.
has an adjustable headrest
or head restraint and you
are using a dual tether,
route the tether around the
headrest or head restraint.
3. Before placing a child in the
child restraint, make sure it is
securely held in place. To check,
grasp the child restraint at the
LATCH path and attempt to
move it side to side and back
and forth. There should be no
more than 2.5 cm (1 in) of
movement, for proper
installation.