I think that's like 14 LED's I see there? About how long does that last battery wise? Usually the white LED's run at a higher voltage than the colored tail lights so you would need to use multiple resistors to wire up a system like that.

Personally I'd run a system like that off a 9V battery using separate resistors for each different LED type all out of one junction box. You can calculate the resistor size yourself or use an online calculator such as the one [link=http://www.luxeonstar.com/resistor-calculator.php]here[/link]. You could alternatively run the LEDs off the main batteries but I'm not sure if this would have a noticeable affect on performance of the car. Just substitute 6V in place of 9V to get the resistors to use based on that type of setup.

My only problem now is finding a way to mount the LED's in the body. I was thinking about drilling and cutting scraps of lexan to fit. Then spray the backside with silver for a mirrored finish and put the LEDs through. Then just glue the whole thing into the back of the body, it would be a bit tricky to get a good fit but I'm sure it could work. If anyone has any other suggestions or what you built yours out of do post them in here. I built a setup for some of my monster trucks but the bodies are quite a bit smaller on these touring cars.