2003 GMC Envoy Owner's Manual - Page 49

Lower Anchorages and Top Tethers for Children (LATCH System) Your vehicle may have the LATCH system. If it does, you'll find anchors (A) in the rear outside seat positions. To assist you in locating the lower anchors for this child restraint system, each seating position with the LATCH system will have two metal tabs where the seat cushion meets the seatback. In order to use the system, you need either a forward-facing child restraint that has attaching points (B) at its base and a top tether anchor (C), or a rear-facing child restraint that has attaching points (B), as shown here. 1-42