Many classic cars have that setup, one fog / one spot - the spot fitted on the side closest to the midline of the road. At least over here it is not allowed any more, all light arrays should be symmetrical and if there is just one single additional light source, it should be placed in the midline of the car. I would have a separate relay for the spots. As a matter of fact, I would have separate relays on the ordinary headlights as well. If your car is from 2005, most likely there are no headlight relays, unless the previous owner fitted them. I achieved a major improvement in light output when I fitted mine.
