Lexus RX300 2003 Owner's Manual page 156

16R314
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.
16R315
CAUTION
Push and pull the child restraint system in different
directions to be sure it is secure.
installation instructions provided by its manufacturer.
2003 RX300 from Aug. 02' Prod. (OM48442U)
Follow all the