Hummer 2005 H2 - Manual (Page 54)

In order to get to the anchor for the center seat in the
second row of an H2 SUT, you may need to fold
the seatback of the rear, passenger-side seat forward.
Use the following instructions.
1. Place the child restraint on the center seat.
2. Fold the rear passenger-side seatback forward.
3. Find the top strap anchor at the rear base of
the center seat and attach the top strap according to
the instructions that came with the child restraint.
Second Row Seats
Third Row Seat
1-48