Hey,
I asked about the mounting a few days ago!
The wire is pretty easy : since i was doing the 6N2 rears i had access to the brake light wires.
When you get the 3rd break light you will notice it comes with a small plug that has two wires. One is the negative. Just connect it to any negative wire you already have in the car ( again, behind the rear lights you have a plug with this wire)
The other wire is the one that makes a connection to the brake. I cant quite remember which one it was but i think it was the brown one.
Best way to do it is get someone to keep pressing the brakes while you make contact with the holes on the plug behind the rear light.
Since i was doing it alone, no one to apply the brakes i thought i got it right the first time but the light was blinking with the hazard lights!!!
But I got it right!
Eventually!
P.S. What you want to do is this, right?
