Beyond the article, I really don't know anything about the alloy content or the process. It sounds they heat the sheet metal so that it will go through the draw die without cracking and splitting. Magnesium in itself is rather brittle. I remember them running aluminum trunk lids on Pontiac 6000s for a while but Indianapolis stamping couldn't get the quality under control and they eventually went back to steel. I kind of doubt that GM would let the cat out of the bag unless they already had a process that works and all their patent ducks in a row. I could be worth a lot of money to them. I've always been curious about how much GM makes on their patent royalties. I would think it would be considerable.
