I love the look of the LED tail lights, like what has become somewhat common on today's production cars. I'd be very interested if you make them a truly unique setup (i.e. not based off the current standard layouts that are out there).
I was actually considering putting something like this together myself eventually (my younger brother has a Masters in Electrical Engineering and was going to help... until he got stationed in Japan). I don't know what thoughts you had as to a layout, but my idea was to build a housing that would be painted (the color of the car) and have inset lenses.
Perhaps you could draw up a picture of the proposed design and post it?