Fuel filler pipe
WARNING: This page is about a different car, the 2003 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
Fuel is filled into the filler pipe and then passes through a check valve and into the tank.
There is an insert at the top of the filler pipe that ensures that the pump nozzle fits well while refuelling. The insert also includes an ejector.