My salesman told me this was normal, but I'm beginning to wonder. I hear a buzzing/humming noise around 30 mph usually when accelerating pretty quickly from a stop. I thought maybe it was a transition from electric to gas power, but now it has started making the same noise while using cruise (or not sometimes) at 60 mph. It is pretty loud. But then fades. Anyone else have it and is it normal? This is our first hybrid.