GMC 2012 Terrain Owner's Manual page 102

3-48 Seats and Restraints
2.2. Route, attach and tighten
the top tether according to
your child restraint
instructions and the
following instructions:
If the position being used
does not have a headrest
or head restraint and a
single tether is being used,
route the tether over the
seatback.
If the position being used
does not have a headrest
or head restraint and a dual
tether is being used, route
the tether over the
seatback.
I n f o r ma t i o n P r o v i d e d b y :
If the position being used
has a fixed headrest or
head restraint and a dual
tether is being used, route
the tether around the
headrest or head restraint.