GMC 2008 Savana Van Owner's Manual page 35

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. In a crash, the child would
not be restrained by the shoulder belt. The
child might slide under the lap belt. The belt
force would then be applied right on the
abdomen. That could cause serious or fatal
injuries. The child could also move too far
forward increasing the chance of head and
neck injury. The shoulder belt should go
over the shoulder and across the chest.
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