Some kind of electric floor? Might look neat, and you have an excuse for glowing cars. Also, you can add sparks.
Sparks!
Have you thought about "shaking" the camera slightly (have it quickly "wobble", etc.) whenever a car explodes and the camera quickly goes back? This can make a game feel a lot more dynamic. You can also try to ever-so-slighty change camera.roll (+-5 at the MOST) when you move the camera to the relative right/left. Again, this makes the camera feel more "alive".
Since I'm by now required by law to add this to any post in this topic: Please add over-the-top 2D-panel-animations whenever points are added or lost (see: Super Smash Bros. Melee).
Perhaps this post will get me points for originality at least.
Check out Dungeon Deities! It's amazing and will make you happy, successful and almost certainly more attractive! It might be true!
