2003 GMC Sonoma Owner's Manual - Page 25

5. To make the lap part tight, pull down on the buckle end of the belt as you pull up on the shoulder belt. The lap partof the belt should be wornlow and snug on the hips, just touching the thighs. In a crash, this applies force to the strong pelvic bones. And you'd be less likely to slide under the lap belt. you slid under it, the belt If 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's a sudden stop or crash, or if you pull the belt very quickly out of the retractor. 1-18