I have a 60 series truck that came with an electric Mico Brake Lock. It has a toggle switch on the dash that controls a solenoid in the brake line. With the switch on, push the brake pedal and the solenoid locks the fluid. It did not always work, so I added a Lever Lock like shown above. The lever is dash mounted. You push the brake pedal and flip the lever up and it holds the brake fluid. Well that is the way is was designed to work. Mine no longer holds the fluid and releases the brakes after about 30 seconds. I can't trust in anymore.
I don't think you would want to add one to a car. Your e brake is enough to hold a car.
I don't think you would want to add one to a car. Your e brake is enough to hold a car.