well the position light is used to illuminate the front of the car so it is easier to notice which end of the car it is when it's getting dark before headlights are required. it's the same as the rear position lights which are red, the front are just amber or white.

the DRL's on the S80's are always on so it defeats this purpose but it's a standard on all cars. on later S80's they moved them from the corners to the center where the hi-beams are. so the bulb is not even connected to any wiring in your car or mine because they are '99's. they must have just found it cheaper to manuf. the later model headlamp assembly and make it compatible to the older models.

but if you wanted to, you can wire a LED directly into the socket of the headlamp.

hope this clears things up.