Alienware M17X R4 chasis material

Hi, I was wondering if any boody knows what kind of materials are being used on the new Alienware M17X R4 chasis. I've heard several opinions on other forums but it seems to be mostly hear say.

I also read that the older models (R3, R2) were maid from Anodized Aluminum and Aluminum/Magnesium respectively, and so it would make sense to me that alienware should continue to use the same or similar alloys on the new M17X R4 chasis since these alloys provide a solid construction, better heat discipation and superior aestethics especially when compared to plastics.

Thanks in advance.