When we were removing components from the car shortly after we got it, we took off the front and rear subframes and corresponding brake lines. Some of them got lost and we also cut a bunch when we were cutting the frame for the motor mounts. On top of that, the original brake rotors and pads were incredibly worn down and needed to be replaced. We just recently replaced pads and reran the brake lines and bled the brakes with new fluid. Now we can stop the car, which is always a good thing to be able to do.
On another note, we had to create our own pedal to integrate with the motor controller. We decided on a single degree of freedom design that allows the pedal to travel without hitting the brake all while properly engaging the throttle controller supplied with the motor.

The accelerator pedal is hinged at the bottom and moves a rod that is attached to the throttle controller on the left.

We also had to make it look interesting.