US vs. Euro headlights.
123 headlights
The different types of headlights that come on W123 cars is explained here.
Use Volvo parts to replace NLA Mercedes parts
If you have a W124 with US-specs headlights and you need to replace the wipers. then you can use VOLVO wipers - #274433
Turn signals
Preventing crashes with amber turn signals.
By Daniel Stern.
Bilux bulbs
Is there a handy source for replacement Bilux bulbs for my 115's European headlights?
Bulbs
What about those brighter bulbs? Yeah, ABOUT them...
Daytime running lights
How daylight running lights are accomplished and why.
Left to right adjustment
For lights that need to be optically aligned (ie, not sealed beams) there are two adjustments: left to right and height. To set the hight you need level ground. But, not for the left-right adjustement.
Rear Fog Lights
REAR fogs? Yup. Explained herein.