anyone know if theres a second bulb already installed on the right for the rear for light and also has anyone figured how to tweak the wiring to get the rear fog light to turn on as well

 

This has been discussed before and I too wanted to do something about it, even though its been made that way by MB to serve a purpose

It's actually a series or row of LED's not a bulb.

It is only fitted to one side of the tail light assembles not both although the tail light itself without the fog light feature does have the same inner parts/shape it does not have the LED's in there.

AFAIK there's only one solution I can think of but it'll only work if the fog light is on different sides in different markets that way you'd source the opposite side and swap it over - I'm assuming but not sure that the wiring would already be in place for either side to be used to suit all markets.

I'll have to check again but here in Aust. the fog is located in the rear right side (looking at vehicle from behind) from what you've mentioned yours is on the left side, if that's the case something like the above can be done.

Can you confirm that yours is on the left side looking at the vehicle from behind and I'll confirm where mine is and go from there