I've been kicking around the idea to modify the sunglass holder to house my accessorie switches for my Hella 700's, undercarriage lights (aka "rock lights") and the electric fans. I have another thread with some pics of the e-fan install and how the lines are run for that. everything is pretty much the same on routing of the wires. Future additions will be bed lights and back-up/side lights.
I've migrated my aux. light switches to the sunglass holder. Connected the 12V source to dome lighting. Which is constant. So, I can turn on the fan and aux. lights without the key having to be in the acc on on position. The 12V source and the ground line is run, I believe the correct term is, in parallel. This makes it look a bit cleaner without a bunch of wires going through the opening. The switch lines were run independently to their respective relays. Starting on the left: driving lights, "rock" lights, electric fan. Here's the pics.