Pontiac G6 2010 Owner's Manual page 79

Sedan Coupe
Retractable hardtop models do not have top tether
anchors to be used to secure a child restraint in any
seating position.
Do not secure a child restraint in a position without a
top tether anchor 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.
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 2-44 for additional
information.
2-49