80 300d lights issue
 

I have a few problems, see if you can help.
My reverse/backup lights are not working. The drivers side light is burned out, but not the passenger side. Mercedes do not require BOTH of them to be good for the other to work does it?
Also, I have euro headlights in (previous owner installed them). The drivers side is dim, while the passengers side is fine. Does the euro bulb just dim over time like an old 50's style bulb does? Where can i find a replacement bulb.
Glove box light doesnt work, but its not burned out. A relay problem?
thanx