My understanding is that the drilled rotors helps, but the audis tend to spec a soft compound steel for the rotor material (brembo, ate are oem suppliers, btw), so not as big of an improvement as you might think. I think dan knows of the folks that are "hardening" the rotors, but they require you buy their rotors (still oem but they won't let you find a "deal set" to send them..... Dan? Scott