I visited the dealer again today. I popped the hood & noticed the color of engine bay is different from the body, so is the back side of the hood & trunk. Steel Gray Metallic & Crystal Gray Metallic have light blueish grey color (it's very obvious). Aspen White (STI) has offwhite color. Obsidian Black Pearl has flat black color. This is the FIRST time I've seen on cars, especially NEW car.
Is it ONLY on 2006 WRXs or Subarus?