I added extra brake lights to these spots, on my 300D w123.



Some members have modified theirs to function the same way Euro w123's do, by adding a rear fog light in the tail light on the same side as the driver, and wiring it up.

However, my observation is that on some units these innermost lenses do not have a proper reflector to bounce off the 21W brake lights, but some do. What happens is these spots will appear slightly darker due to less reflected light.