I was cleaning out the interior of the car today and when I was cleaning the indicator switch I had it held down in the '3 flashes' position, after a few seconds the car made a 'bong' sound like when its low on oil or the such like.  At this point the key wasn't even in the ignition.  I pushed the switch up the other way and sure enough it made another 'bong'.  Any ideas on what this is for?