Chevrolet 2003 Malibu Owner's Manual page 32

The safety belt locks if there's a sudden stop or
a crash,
or if you pull the belt very quickly out of the retractor.
too loose. In a crash, you would move
forward too much, which could increase injury.
The shoulder belt should fit against your body.
To unlatch the belt, just push the button
on the buckle.
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