 I have a Mazda 3 Sky active with 25000 kilometers on it.  The hood has developed numerous small rust spots on it.  There are also small areas where the clear coat is peeling off the paint.  The color is Graphite gray metallic.  The car has been well cared for and is not abused in any way.  The fuel economy is good, but not as good as advertised, otherwise love the car.  The rust has continued to grow, and I have ordered a carbon fiber hood to replace it, as once started rust cannot be stopped.