Les Barrett

Can anyone help. ? Just bought my first Corsa, 2007 petrol Design 3 door. Its showing signs of needing a new fuel filter. But the problem is I cant find it. Diesel filter is in the engine bay. Petrol filter is under the car by the rear drivers side wheel. Except its not. I have been under there with a torch and there is no sign of one. So where is it ? I have a new one in the post but no idea what to do with it when it arrives . Does anyone know ?