Lexus GS300 1998 Owner's Manual page 249

AIR CONDITIONING AND AUDIO
20L021
3. Pull out the tray while pushing the lock release button.
20L022
4. Put a disc on the tray with its label face down and push
the tray back into the magazine.
If the label faces up, the disc cannot be played. In this case,
"Err" and the disc number appears on the display.
236