Lexus RX300 Manual page 223

IN CASE OF AN EMERGENCY
Access to spare tire
40R053b
1. Pull up the deck board.
208
40R054a
2. Take off the hook at the rear of the deck board.
3. Lift up the back side of the board and secure the board by
hooking it at the top of the back door opening with the hook at
the edge of the strap.
Make sure the board is secured and does not fall down.