For liscnese plate stop lights, are you talking about something like this?
http://www.aerostich.com/catalog/US/Sto ... 16981.html
If I do change my mind and opt for extra brake lights, all I, or anyone else, need to do is splice into the Black wire with the white stripe. That's the brake line. As I said, the brown line is the running line.
I don't know why they use so many different colored lines. I understand in keeping systems separate so you can find certain wires. But, back in the day, I remember all ground wires being black and hot wires being colorful. Oh well. It works.