The outer air vent bars on my 2011 E250 W212 Blue-Efficiency Sport are silver coloured. The result is that in daylight they are always clearly visible as a strong reflection in the outside mirrors. This reflection is most pronounced in the driver's mirror. When I place my hand over the vent the reflection disappears. The safety view both visually and psychologically is then much improved. In my opinion this is a safety issue and one that that M-B should never have designed-in. I'll post a photograph of the effect tomorrow as it is too dark to do so just now.