sounds like someones had an original driving light rust out on them, and have replaced it with the japanese or american relase fog light. the fog lights have a more dispersive lens, and have that bulb 'umbrella' in them. youll probably find theres also a yellow bulb cap under there too.
trying to get an australian issue plain lens driving light is bloody impossible. they rust out easily, and everyone wants them. not thats theres many available to start with.