I know there are many tutorials for installing the rear fog light, but this is how I chose to do it. It combines the convience of having a Nissan switch without having to pay almost $200 for the kit from The Z Store. It also utilizes the vast majority of the factory harness.
I referenced many DIY threads on this topic and much thanks to all those for their ideas and research.
1) Buy the rear fog light and install as per other threads. Connect it to the factory harness sitting there waiting for you.
2) Purchase the switch to work the Fog Light. It is an ON-OFF SPST switch with illumination (when headlights are on). No LED is required to be installed to tell if the Fog Light is on because you can tell from the position of the switch.
The switch is actually a "Cargo Lamp" switch from a Frontier/Armada/Titan, but if you can get over it saying Cargo Lamp, it's great and the illumination is orange and matches the car. I was unable to find the switch used in the expensive harness from The Z Store which has a Light symbol instead.
This is the switch you need
Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com
3) Next, run the fog light wire from the BCM to the switch. You want to tap the wire, then cut it free of the BCM. The wire I am talking about is the orange one. See this thread for details
DIY: Rear Fog Light Wire Via BCM and Stock Wiring
When 12V is applied to this wire, the fog turns on.
4) My car didn't come with heated seats, but the harnesses are there under the cupholder. 2013+ MYs have these, I can't vouch for older years.
Regardless, if the heated switch harnesses are there, you can tap the 12V+ wire from the heated seat harness (only energized when Ign is ON). If no heated seat harnesses, you can tap the cigarette lighter in the console for 12V.
Next, you can also tap the heated switch harness for the illumination circuit so the new switch lights up when your headlights are on. If no heated seat harness, you will have to grab it from another switch.
5) So you now should have 4 wires connected to your new Cargo Lamp Switch: 12V in controlled by the ignition, the orange wire from BCU to power the fog light, and ILL+ and ILL- for the nighttime illumination. Flip the switch once the car is ON, and you'll have light.
I rushed typing this so any questions please let me know. Also, the pin-outs for the heated seat switches and cargo lamp switch are completely different. Just ask and I'll post the pinouts and which wires to tap. Just be sure when you tap the orange wire at the BCM and run it to the new switch that you cut it/disconnect it from the BCM.
Hope that helps some of y'all out there!