Metallic whine is a completely normal noise on 3IS 350 F-Sport. All of them have it and it is really annoying but totally healthy. Cant do anything about - it is just the way it is. Recently had a chance to drive bmw m235i and boy does it sound sweet.
Audi 8V S3 Sepang Blue - 19 Performance Pack - Advanced Tech Pack (currently own)
2014 Lexus IS350 F Sport - Ultra White - Rioja Red - Nav/ML/BSM - F Sport Exhaust - Full Tint - Clear Bra/Xpel Ultimate - F Sport Intake (traded it in)