Love it! Mixed material manufacturing is not new for GM. Using the right material where it counts is another phrase. Aluminum spot welds, and flow drilling patents are all in use today. High pressure casting and laser welding of dissimilar metals.... You can find great videos and info on this by looking up the Cadillac CT6. May be a heavy use of aluminum but do not think of it like a pop rivet connected vehicle like some of the competition.
Or a thought process of having to use aluminum only if it is not a good idea in that area.