I have an arctic white 2.5 sport (#1425). I have noticed that after driving a short distance, a light black dust starts to build up on the rear of the car (and to a lesser extent behind the front wheels). If you drag your finger along the rear fender after driving 20 miles, it will come up black. If I use detailing spray every few days the towels turn black. I am assuming that this is the tires wearing away?? Have any of the rest of you seen this, and does it go away? I have the Yoko Advan 07's. It really builds up heavily under the rear clamshell on top of the PEM and Battery. Thanks for the continuing advice to a new owner.