Since you are adding the light, go the extra step and replace the bulb with an LED replacement bulb. Takes a lot less power, and creates a lot less heat.
You can also add in a flasher that blinks the light a few times before it goes solid. Sort of like this idea. Here's a source, although you can find some cheaper on Amazon or Ebay. I like this company's product, especially their "delay" product. It flashes a few times, then goes solid. If you re-apply your brake within 8 seconds of releasing it, like in stop and go traffic, it does not flash- just goes solid. Won't drive the people behind you crazy.
http://kahtec.com/------------------
'87 GT , '00 3800 Series II SC, 4t65e, Vue Power Steering. (SOLD)