BEN-GS300

To this day this is still the tightest GS i've seen. My inspiration for getting my very own 3GS a few years back and have had no regrets!

http://www.clublexus.com/forums/cl-of-southern-california/639066-lexus-toyota-car-club-in-los-angeles.html

I had this problem as well. I looked into it myself and noticed that the holes on the disc (aftermarket) where the wheel studs go were significantly bigger than the studs on the hub, this meant that the disc could move around before resting on the studs to stop the car. When driving in a linear motion they disc would already be lying on the stud but when you turn, the disk moves around some before making contact with the studs. I bought the origonal discs from the dealer, threw them on and the noise went away. Look into it and see if the hub moves around when you take off the wheel.