* Turn the ignition off: This is the primary way to stop fuel flow. The fuel pump will shut off.
* Disconnect the fuel pump relay: This is a more involved process requiring some mechanical knowledge and access to the underhood fuse box or relay center. This will stop the pump from running.
* In a severe emergency (e.g., fire): If the car is on fire, focusing on getting away from the vehicle is far more important than stopping the fuel flow.
There's no readily available manual shutoff valve like on some older cars.