From the front of the car facing backwards it is in the far right corner. It will have a metal top which when removed will have 2 opposite sides to locate in the reservoir. There will also be a narrow tube near the top to allow any fluid to be released if the pressure exceeds the rating of the cap.
Release it anticlockwise (about 1/2 turn) and you will see a red sleeve inside. Fill between top & bottom of this sleeve.
There will probably be like a big plastic nut to the left of the filler cap which has 2 wires - this will be the level warning switch.
Steve
April 2007