GMC 2006 Savana Owner's Manual page 54

Third or Fourth Row — Three Passenger Bench Seat
There is a top tether anchor for the front passenger
position with a front passenger seat. The anchor
is located at the rear of the seat cushion on the right
front passenger's seat.
1-48
Front Passenger Position
There are no top tether anchors or lower anchors in a
four passenger fourth or fifth row seat.
Do not secure a child restraint in the outside seating
positions of the third and fourth rows if the vehicle has a
three-passenger bench seat, or in any four-passenger
rear bench seat, if a national or local law requires
that the top tether be attached, or if the instructions that
come with the child restraint say that the top tether
must be attached. There is no place to attach the top
tether in these positions.