Chevrolet 2001 Impala Owner's Manual page 69

CAUTION:
Never do this.
Here a child is sitting in a seat that has a
-
lap shoulder belt, but the shoulder part is behind
the child. If the child wears the belt in this way,
in a crash the child might slide under the belt.
The belt's force would then be applied right on
the child's abdomen. That could cause serious or
fatal injuries.
Wherever the child sits, the lap portion of the belt
should be worn low and snug on the hips, just touching
the child's thighs. This applies belt force to the child's
pelvic bones in a crash.
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