I know this is bringing up an old thread, but I feel it is pertinent. I haven't found Veloster-specific wiring instructions for the two additional wires. This is for if your Veloster does NOT have the sunroof controls in the map-lights. My 13 nav was stock. The map lights have only three wires in a 4-pin harness,Yel(pin3)/Red(pin2)/Blk(pin1). The red is always on 12V. And the Yellow is 12v switched by IGN. I hope this will help anyone doing the auto-dimming mirror with Homelink upgrade.