audia6s

I am going to wire aftermarket DRL lights to my A6. Along with the light I am going to install dimming module. The dimming module will light up aftermarket DRLs about 50% when the headlights are turned on and 100% when the headlight are off. The module requires for one of the wires to be connected to "ignition controlled power source" meaning I need to run one wire from "headlight" area to the fuse box as it is the safest place I would think. Can anyone tell me the best and easiest way to run the wire into the car's cabin? Thanks