I just did this mod using a 48 LED panel inside the dummy lens and housing, and I am quite please with the results. It is currently wired up to come on with the parking lights, though I plan to wire up a switch to the center console as well as flash it in reverse whenever I have time to figure it all out. I will definitely post if I do it.
Here are some a few things I did differently, and you can see a few more pics in my album
here. I should have taken more
OP's Step 5. I used a 48 LED panel which came with adhesive on the back, so I mounted it to what is the ceiling inside the housing when the fog light is installed. This way you never see the LEDs unless you're practically lying on the ground.
OP's Step 6. I'm not sure if it's the flash, but my housing was much more gray than the OP's. I had some Rustoleum gloss white laying around, so I spray painted it with 2 coats for brighter reflection. I then ran the wiring through the tiny hole in the housing where it has the black cap on the outside. I decided to pry off the cap, run the wiring through the hole, and replace the cap over the wiring.
OP's Step 10. I ran the wiring between the metal and styrofoam of the rear bumper to keep it away from the exhaust.
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