Chevrolet Optra 2005 Owner's Manual page 44

Wagon — Center Position
You will find the anchor (A) for the center seating
position on your wagon, on the ceiling (B).
1-38
Each top strap anchor is covered by a plastic cover
when not in use.
Squeeze and pull the front part of the plastic cover to
access the top strap anchors.
The plastic cover has a
child restraint anchor
symbol on it as shown.