Cars driving in a rectangle.

I liked making the car go in a rectangle, but it was a little frustrating. It was frustrating because everytime I would test the car, it would not go into a straight line, it would go in a diagonal line. The obstacles were that the two motors could have had a different friction, causing one to run differently than the other. Another obstacle was the time of how long the car would go foward with each turn. To correct the deficiency of the time, I just kept testing how the car ran with different times to get it as close to a rectangle as possible. I think to make it work better you could make sure that the friction of the two motors are as close as you can get them to being the same.