There are two female eletrical connections just behind the knob inside the shaft of the headlight switch, it would seem to be a way to illumanate the orange lense in the center of the knob, if there was a bulb. The car is a U.S. model 1990 300-E
So does anyone know the story here.
Or the specs of the bulb?

Thanks
Tim

Don't know about the connections behind the switch, but FYI the orange lamp in the middle of the knob lights up when you turn on the fog lamps - by pulling the knob towards you prior to turning it like usual.

Cheers.