Chevrolet 2010 Impala Owner's Manual page 78

2. If the child restraint manufacturer recommends that
the top tether be attached, attach and tighten the
top tether to the top tether anchor, if equipped.
Refer to the child restraint instructions and
the following steps:
2.1. Find the top tether anchor.
2.2. Push on the depression at the rear of the
cover and swing the lid open to expose the
top tether anchor.
2.3. Route, attach, and tighten the top tether
according to your child restraint instructions
and the following instructions:
2-48
If the position you are
using has a fixed headrest
and you are using a
single tether, route the
tether over the head
restraint.
3. Push and pull the child restraint in different
directions to be sure it is secure.
If the position you are
using has a fixed headrest
and you are using a
dual tether, route the tether
around the head restraint.