Mercedes-Benz 2008 GL 450 Operator's Manual page 499

Practical hints
Unlocking/locking in an emergency
Insert a suitable object such as a coin
into the slot of lock 1 ( page 497).
Turn lock 1 counterclockwise by 90°
in direction of arrow.
Remove cover 2 ( page 497).
3 Fuel filler flap release
498
Pull red fuel filler flap release 3 in
direction of arrow.
The fuel filler flap is unlocked.
Open the fuel filler door ( page 374).