In some non-UK markets the fog light is integral to the rear position lamp (hence the rear position lamp bulb is a 21w & 5w twin filament but only the 5w is used in the UK).
Due to UK & EU regs on fog lamp positioning (i.e. must be minimum 100mm separation with the stop lamp) it was moved to the bumper reflectors.
Although UK cars only had one fog light (o/s) you can buy from Volvo a kit to implement the nearside as well - you need a wiring loom, lens and bulb holder.
You need:
LH Drive rear fog lamp body part number 31213647
Fog Lamp bulb socket / harness part number 8693010
And here is how (end of thread)
https://www.volvoforums.org.uk/showt...oglight&page=2