If you are going to race that thing, be sure to change out the brass rings in the front suspension and in the steering for bearings. I believe the 5X8mm is the size that you want. It drastically increases the smoothness of the front suspension and your steering response. I found the car to be much smoother and easier to control with the bearings.
Looks like you have done a good job! Just be sure to switch what has already been pointed out and be sure to let us know how it runs when you take it out for a spin! These cars run REALLY well when you get them set up properly, and as a plus, they take ALOT of abuse on the track!