Mazda 2002 B2300 Owner's Manual page 113

Lap belts
Adjusting the center lap belt
The lap belt does not adjust automatically.
WARNING: The lap belts should fit snugly and as low as
possible around the hips, not around the waist. Failure to
position the lap belt correctly may cause serious injury in an
accident.
Insert the tongue into the correct
buckle (the buckle closest to the
direction the tongue is coming
from). To lengthen the belt, turn the
tongue at a right angle to the belt
and pull across your lap until it
reaches the buckle. To tighten the
belt, pull the loose end of the belt
through the tongue until it fits
snugly across the hips.
Shorten and fasten the belt
when not in use to keep the belt
away from door openings and
available after unfolding the
seats.
Adjusting the rear center facing jump seat lap belt (if equipped)
The lap belt will adjust automatically. To fasten, grasp the tongue, and
with a continuous motion, pull out enough webbing to buckle the tongue
into the correct buckle. If you did not pull out enough webbing to reach
the buckle, allow the tongue to retract fully before trying to pull it out
again.
Seating and Safety Restraints
113