trailer electrical wiring

hello fellow suby owners, i'm silvo, from NSW, Australia, recently bought an '00 impreza rx auto hatch. It has a "genuine" Subaru towbar. It has "SUBARU" and the compliance information stamped on it. It was fitted prior to delivery I'm told but I can't find the trailer lights socket to attach...

I have this plug in my Outback with all the wires live that are required for a trailer plug. Just wondering if it is possible to get a plug to fit it? My auto shop had no idea. And I can't fins a plug that looks the same as this on the internet.