just noticed this this morning.... if you have headlights and rear fog light on, when you turn the headlights off, the fog light also clicks off at the same time. similarly if you just turn the fogs on without turning the headlights on, it will automatically click on the side lights - however you then need to use the headlight control to switch on dipped beams.
Never noticed this on any of the other 6 cars i've owned! useful way of preventing you from forgetting to turn off your foglight, but i'm yet to see a use for having rear fog light and just side lights on... probably cos its too difficult to make one turn of foglight toggle automatically do two turns of headlight toggle.