Lexus 2003 LS Owner's Manual page 178

COMFORT ADJUSTMENT
16L320
3. While pressing the convertible seat firmly against the seat
cushion and seatback, let the shoulder belt retract as far as it
will go to hold the convertible seat securely.
164
16L321
CAUTION
Push and pull the child restraint system in different
directions to be sure it is secure.
installation instructions provided by its manufacturer.
Follow all the