The first modification we made was we cut the square into two triangles. One on the back of the car and one on the front. We did this to distribute the weight evenly throughout the car. If there is too much weight on the back it creates more drag. The car went 23 feet which is better than the 8 feet of our original car.
The cardboard on our car was bending when we wound up the car. So we added wooden sticks on the cardboard so that it would not bend and so the car was stabilized. After that the car went 34 feet.
We realized that that the wheels were crooked so we changed how they are connected to the axle and the car went 43 feet. This improved the efficiency of the car because it made the car go straight, not in a crooked line.
We realized that the rubber band was wearing out so we tried a new rubber band and the car went 55 feet. This rubber band was slightly thicker but the same length as our previous rubber band.
This is our final car and the furthest distance was 55 feet.