Chevrolet 2006 HHR Owner's Manual page 52

The top tether anchors are located in a storage
compartment behind the rear seats. Lift the lid of the
storage compartment to access the anchors. 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.
1-46
If the vehicle does not have rear seats, there will be a
top tether anchor for the front passenger position located
on the floor behind the front passenger's 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.
Do not secure a child restraint in the right front
passenger's position if your vehicle has rear seats, if a
national or local law requires that the top tether be
attached, or if the instructions that come with the child
restraint say that the top tether must be attached.
There is no place to attach the top tether in this position.
Accident statistics show that children are safer if they
are restrained in the rear rather than the front seat.
See Where to Put the Restraint on page 1-41 for
additional information.