I recently began doing this project on my 6s. The reflectors right above the tail lights can be illuminated from behind, you just need to use some creativity to make it work. Attached led bars to the brake wire and created a small bracket attaching it with two step appoxy to mount the leds.
The best thing to use would be leds. I am using ones from http://www.radlites.com/led_strips_boards.htm
They are for the most part inexpesive...i would just buy the leds myself and wire them but i kinda wanted a pre-made unit that was resistant to water so i bought these rubber coated ones so i dont have to mess with making it water tight.
You can probably get away with using the 3 led bar because the reflector should evenly distribute the light, but it is a new car and you might as well spend the extra $5 to get the 9 led bar...it is soo much brighter and looks nicer. (9 led bar cost $34 so for two you are looking at about $60) Not to bad of a price...although if anyone knows where to get small led strips ( cant be too long or wide 4 inches is the limit) like this that are brights and a good quality for cheaper would be nice.
Now i do know that there is a law that prohibits the number of lights on the front and rear of your car for sure. I think that in the front it is a limit of 4 light>reason why our fog lights turn off when the high beams are put on, and in the rear it is 3. The law also says what height the lights in the front and back must be from the ground(dont remember exactly what it is.) Dont know if these are laws in all states, but here in Jersey they are...we have laws on everything.
BUT do the mod anyway who cares...most police officers will not even notice it is a problem for the most part, and if they do they will not probably pull you over for just that. And if they do just sweat talk your way out of it and say you can never be too cautious and that your old car was rear ended and now you are paranoid about it.
I am trying to post pics with this but they will not load so anyone please help me on how to post them.
As soon as i get back from school i will try and make detailed instructions for this mod....till then feel free to post pics if you have done it youself and instructions if you have the time...thanks.