The flat, disc-like surfaces on the both sides of the Volkswagen brake rotors are the location where friction is created to stop your vehicle. On all Volkswagen models there are two disc brake rotors as part of the front wheel assemblies. On most other models they are also located on the rear wheel assemblies. This surface of the Volkswagen disc brake rotors will remain smooth just as long as the contact from the pads is done with the padding material on them is intact. When this padding material wears out, they have to be replaced before the metal backing plate comes in direct contact with the brake discs. If direct contact with the metal backing plate of the brake pads does occur, each time the brake pedal is depressed the brake rotors will be damaged on your Volkswagen. The damage that occurs to the flat rotor surface is when grooves are cut into it by the metal backing plate of the brake pads. The driver of the Volkswagen will be fully aware of this occurring because of the loud grinding noise that is emanation from the wheel assemblies. If a brake job is not scheduled when this is heard, it should be made very soon. The longer this condition persists on your vehicle the greater the damage being done will occur. During the next brake job, the brake rotors and discs will then have to have to be resurfaced and turned on a lathe. This process involves applying an abrasive force to the rotor surface so that all the grooves and inconsistencies are eliminated. If the grooves are too deep, the rotors will then have to be replaced to restore the integrity of the braking system on your vehicle.