I have been wanting to control my factory fog lights separately also so I looked finding this dang elusive fog relay myself today.I couldn't find it either!! Doh!
According to the manuals and looking up under the dash......It seems the fog relay is different then the 4th Gen in that it is housed inside what they call the Main Body ECU.

The Main Body ECU is a little black box up under the drivers side dash. From what I saw and it comes out as a unit and the relay is probably inside as there is a pretty big wiring harness plug going to it.

Help!!!! To all you wiring diagram reading Spark Chasers.....From the factory wiring diagram,page 233
What does the shaded gray area mean,what does FFGO mean coming off the ECU and why does it seem like the tail light activates the fog relay???

I'm going to look into it again tomorrow night to see if I can pull that main body ecu out to find the relay.

I may just wire up my own relay on it's own circuit and switch for the fogs like I did for my PIAA fogs.I have some pre-wired Bosch/Tyco relays just lying around not being used anyways. I'll just pull the 15 amp fuse for the factory fog circuit, as I did find that up under the dash, and be done with it.