2007 Pontiac Grand Prix Owner's Manual - Page 24

6. To make the lap part tight, pull up on the shoulder belt. It may be necessary to pull stitching on the safety belt through the latch plate to fully tighten the lap belt on smaller occupants. 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 would 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 is a sudden stop or crash. 24