Buick 2009 Enclave Owner's Manual page 32

Lap Belt
This part is only for the lap belt. To learn how to wear a
lap-shoulder belt, see Lap-Shoulder Belt on page 1-22.
You vehicle may have a center seating position.
When you sit in the center front seating position, you
have a lap safety belt, which has no retractor.
To make the belt longer, tilt the latch plate and pull it
along the belt.
Buckle, position and release it the same way as the lap
part of a lap-shoulder belt.
1-28
To make the belt shorter, pull its free end as shown
until the belt is snug.
If the belt is not long enough, see Safety Belt Extender
on page 1-29.
Make sure the release button on the buckle is positioned
so you would be able to unbuckle the safety belt
quickly if necessary.
If you find that the latch plate will not go fully into the
buckle, see if you are using the correct buckle. Be sure
that the latch plate clicks when inserted into the
buckle.