Make sure you solder 3 ceramic capacitors of 0.1uF (100nF) on each motor like this: one capacitor between the motor's leads, one capacitor from one lead to the motor case, ant the third capacitor from the other lead to the case. This is for reducing the motor noise in your electronics and to extend the motor's life. Also, twist the wires going from the motor to the motor driver.
Good luck with your project and let us know how it turns out! (pictures, video...)