To bad we can't see the music coming out from the earphones.. so you should record them and put it in here as a download
looking forward to the results. And is it going to compete at modelshows?? Because maybe working lights and some light underneath the car (like some of the real streetracers have) could be very cool looking. The hole and the box for the wires and batteries are already in the planning of your model, so that would be not so hard. Only getting the lights in would be difficult i guess.
But since your are modding this car so much, lights should not be forgotten