Pontiac 1998 Grand Am Owner's Manual page 22

The lap part of the belt should be worn low and snug on
the hips, just touching the thighs. In a crash, this applies
force to the strong pelvic bones. And you'd be less likely
to slide under the lap belt. If you slid under it, the belt
would apply force at your abdomen. This could cause
serious or even fatal injuries. The shoulder belt should go
over the shoulder and across the chest. These parts of the
body
are
best
able to take
belt
restraining forces.
The safety belt locks if there's a sudden stop or crash.
Shoulder Belt Height Adjuster (4-Door Models)
Before you begin to drive, move the shoulder belt
adjuster to the height that is right for you.
To move it down, squeeze the release button and move
the adjuster to the desired position. You can move the
adjuster up just by pushing up on the shoulder belt
guide. After you move the adjuster
to
where
you
want it,
try to move it down without squeezing the release
button
to make sure it has locked into position.
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