set_motor_speed Function does not work properly

[runnam]

When using the set_motor_speed function there are a few issues. First is that the motors are reversed. Inputting motor 1 moves motor 2 and vice versa. The other issue is that you cannot control the direction of the motor. I have tried with multiple pi-cars and they all move the motor in a fixed direction that doesn't change if you put in a negative or positive motor speed.