Chevrolet 1997 Astro Owner's Manual page 72

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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