nice concept, but i think the perspective is off, cant quite place it.... anyway to make good neon, start by selecting part of the bg under the car and saturate that with color then brightness/contrast it and then add that color blob that you have now for neon
play around with it and it should look good :P
the drivers are way too bright, its night out and the windows reflect all the street lights so...just make vague shapes of people dont use full detail