I've heard that drilled rotors will make noise, maybe others can chime in with their experiences. My Dad's Toyota Avalon had a hum noise after getting new rear rotors, one rotor had curved machine marks and they were just enough to make a hum. Another new rotor fixed it. If your pads are new as well, some "breakin" is needed, like some stop and go and expressway driving. If your car was parked, there might be some rust on the rotors, too.
