2002 GMC Sonoma Owner's Manual - Page 56

Anchor the top strap to one of the following anchor points. Be sure to use an anchor point located on the same side of the vehicle as the seating position where the child restraint will be placed. If you have an adjustable head restraint, route the top strap under it. When using a top strap-equipped child restraint in a rear outboard seating position of a crew cab model, route the top strap through the opening in the head restraint. Then, attach it to the anchor point for that seating position. Once you have the top strap anchored, you'll be ready to secure the child restraint itself. Tighten the top strap when and as the child restraint manufacturer's instructions say. In Canada, the law requires that forward-facing child restraints have a top strap, and that the strap be anchored. In the United States, some child restraints also have a top strap. If your child restraint has a top strap, it should be anchored. 1-49