some come with a kit that is designed to run tubing to the brake rotors (they actually fit onto the stub axle. If you are not tracking the car you will not need it anyway. probably not of great use on track either until you start pushing on a bit.
Mine have a length of tubing that is run from the air duct along the side of the wheel arch and is "pegged" in by a small metal plate to stop the tubing fouling the wheels at full lock from the plate the tubing goes directly to the stub axle, there is a blanking plug that would need to be removed before you fit the tube. the tubing is secured to the stub with a jubilee style clip.