It is under the windscreen wiper scuttle in the engine bay. You will need to remove the wiper blades before you can remove the scuttle. Make sure you mark their position on the windscreen with a piece of stickytape before removing. I advise geting hold of a windscreen wiper stalk remover tool because it can be an absolute pain in the @$$ getting these off by any other means! I was there for over an hour removing the passenger side one! Ended up using a piece of rope, and 2 strong bodies. Once off, there are two plastic clips holding the scuttle down, one at each side of the scuttle. Lever these out carefully with a screwdriver and the scuttle should come away in two parts. Be aware that there are also 2 plastic lugs, one at each side, which secure the scuttle in to the wing of the car. Be careful not to snap these by forcing the scuttle panels off. The shorter side comes away first. My heater motor is on the passenger side.
TEfLoN, June 2006