However be careful on the style of CREE led you buy: Reason is ...sedan socket looks like this / \ (facing the sides) and not straight back | | .
If you want to use CREE led.. get something like this: It has cree leds on top and also the sides.
Do Not get something like this:
This type.. the light out put is very directional and so you will get zero light output right behind your car.. instead all the light will be focused on the side of the car.