After refueling, turn the fuel tank cap until you hear a click. Once the cap is released, it will turn slightly in the opposite direction.

Caution
When replacing the fuel tank cap
Do not use anything but a genuine toyota fuel tank cap designed for your vehicle. Doing so may cause a fire or other incident which may result in death or serious injury.
Opening the fuel tank capComponents
(2005/11-2006/01)
...
Inspection
Inspect automatic transaxle oil panel
sub-assembly
Remove the magnets and use them to collect any
steel chips. Examine the chips and particles in the
pan and on the magnet to determine what type of
wear has occurred in the transaxle.
Steel (magnetic): bearing gear and plate ...
Reassembly
Caution:
Wear protective gloves. Sharp areas on the seat frame
(with adjuster) may injure your hands.
Install front seat wire
Install seat position airbag sensor (see
page rs-390)
Install lumbar support adjuster assembly
Install the lumbar support adjuster with the 2
screws.
...