I just purchased a 2003 SL500. On the top of the headlight switch where it has the headlight symbols and the word "auto", are those symbols supposed to illuminate when the headlights are on? I called Mercedes customer service and they said it should but when I took the car to the dealer, they said it doesn't. The center of the headlight switch knob lights up and the two bottom green lights turn on. Any help on this is appreciated.