Chevrolet 2009 HHR Owner's Manual page 54

2.3. To secure a child in the front passenger
position, only if your vehicle does not have
rear seats, find the top tether anchor located
on the rear passenger side pillar behind
the front passenger seat.
Be sure to use an anchor located on the
same side of the vehicle as the seating
position where the child restraint will be
placed.
2.4. If the position you are using has an
adjustable headrest or head restraint, raise it.
2.5. Route, attach, and tighten the top tether
according to your child restraint instructions
and the following instructions:
1-50
If the position you are using
does not have a headrest
or 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 headrest
or head restraint 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,
raise the headrest or head
restraint and route the
tether under the headrest
or head restraint and in
between the headrest or
head restraint posts.