Is it the same on all Mercedes? Our Viano only illuminates the driver's side rear fog light. The bulb is in place on the left but doesn't light up. The bulb is OK so is it standard for only the offside to light up and can you select the near side if wanted, for example driving in France or even better can you have both together, or do you have to have it done by MB dealer? The nearside has never worked and there has never been any error message which I think there would be if there was a fault.