2004 Buick Rendezvous Owner's Manual - Page 46

3. To make the lap part tight, pull down on the buckle end of the belt as you pull up on the shoulder part. 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 pelvic bones. And you'd 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. 1-40