There are Lexus brake rotors and discs on all front wheel assemblies and many rear wheels of this luxury car brand. This is the solid braking component that the disc brake pads will be forced against causing friction that will stop your Lexus. The surface of the Lexus brake rotor and discs has to remain flat and smooth for the life time of your vehicle. This will not only minimize the wear on the brake pads but also permit the brakes to operate at a cooler temperature. The only way the brake rotors and disc can be damaged is when the brake pads are not replaced when they are worn out. The owner of a Lexus can protect their brake rotors and disc by keeping an eye on the wear of the pads. This can be done with a visual inspection of them by removing the wheels and looking at them when they are in the calipers. If there is less than a 1/4" of padding left, then replacement is warranted. A simpler way to guess at the wear on the front brake pads to help protect your brake rotors and discs is to look at the back reservoir of the master cylinder. This is the brake fluid for the front braking system. When the fluid level is low, it has moved to occupy the space of the pads that has worn away. If you feel some brake fluid should be added, first have the front brakes checked. If the brake rotors and discs are damaged by contact with the metal backing plate of the pads, it can be removed by having them turned on a lathe. This can only be so many times before the rotors became too thin and would then have to be replaced for your Lexus to be safe on the road.