there is a DRL module in the car.
I was reading up on it in the CD manual the other day for the W124.
It appears it plugs into the back of the gauges cluster through a bulb, and possibly some of the wiring.
These are for the 1995 E320 W124 Chassis car.
Function of Daytime Running lamps
http://www.a-p-group.com/ashman/pdf/82-0070.pdf
Retrofitting Daytime Running Lamps
http://www.a-p-group.com/ashman/pdf/82-0071.pdf
Alon