I have a 2000 s430 and the lower left outboard taillight stays on even after shutdown and key removed. Only way to get it off is to pull the plug. No malfunctions are noted... So what is wrong, how do I fix? I have searched here with no answers.

Thanks in advance.

on edit: apparently the left front amber is also stuck on in addition to the rear red

 

I encountered this and discovered it wasnt a problem, but rather a "feature" of Mercedes cars. Is your headlight switch pointed straight up and down, or turned all the way to the left?

Mercedes and some other European cars have this feature, to leave the left side lights on (for when parked on narrow European streets) - it is activated by turning the headlight switch all the way to the left. The "Fully off" position for the lights is with the switch straight up and down (ie the middle position, not the far left detent).

If your headlight switch is not turned all the way to the left, and is in the OFF position (straight up and down) you may have a bad switch.