Lexus 2004 GX470 Owner's Manual page 385

STARTING AND DRIVING
(d) Backing up
"
1 Brake pedal 2 "R" (Reverse) position
NOTICE
Never shift into reverse while the vehicle is moving.
When the shift lever is shifted into "R" position, the outside rear
view mirrors automatically down to help backing up. For
details, see page 205.
370
1. Bring the vehicle to a complete stop.
2. With the brake pedal held down with your foot, shift the
selector lever to the "R" position.