There were a few problems I faced. The first was that when I input the code for the car to move front and back, the car would only move backward. I tweaked the car a lot but I soon realized that the problem was not in the wiring, but in fact in the code. The second was that the line reading unit at one end of the car was not functioning properly and was often derailing. After a lot of research, I soon figured out that the wire giving power to the sensors at the bottom of the car was loose. With a simple tightening fix, the car was working better than ever.