Pontiac 2005 Montana Owner's Manual page 79

You will be using the child restraint's harness (A)
to secure your child. Do not use the vehicle's
safety belts.
{
CAUTION:
Using the vehicle's regular safety belts on a
child seated on the built-in child restraint
cushion can cause serious injury to the child
in a sudden stop or crash. Secure the child
using the built-in child restraint's harness.
WARNING: FAILURE TO FOLLOW THE
MANUFACTURER'S INSTRUCTIONS ON THE USE
OF THIS CHILD RESTRAINT SYSTEM CAN RESULT
IN YOUR CHILD STRIKING THE VEHICLE'S
INTERIOR DURING A SUDDEN STOP OR CRASH.
SNUGLY ADJUST THE BELTS PROVIDED WITH THIS
CHILD RESTRAINT AROUND YOUR CHILD.
1-73