Yes, OEM fogs go in the lower corners of the bumper where the "blanking plates" are at. If you want to install OEM fogs, you have 1 of 2 options, either buy the complete kit from Ford, $200+ dollars, or buy the pieces individually, option #2 is cheaper. The pieces that you will need are the fog lamps themselves w/ the mounting brackets, lamp bezels, fog lamp relay, and an OEM switch that is set up for fog lights. The istall is pretty simple, once you get it all figured out.
Here is a pic of my Focus before installing OEM fogs:
Here is what my fogs look like installed:
If you notice, my bezels are silver, to match the car, I had them painted, stock bezels are black like your blanking plates. The ZX4 ST bezels are black with the ring around the lamp being silver.