Few interesting points come to mind after watching that.
1. Quality. By moving all the carbon production in-house, they are controlling the quality. They obviously learned from Boeing's mistake of farming out carbon production all over the world for the 787 components.
2. Scale. They are fully committed to moving to composites for their city vehicles and ditching steel eventually. Composites have equal strength as steel, half the weight, and better energy absorption in a crash. I'm sure this is not an overnight process, but it looks like a substantial investment already.
3. Future vehicles. This much effort is not for making little spoilers and trim. All the rumors of the 3 and 4 cylinder motors - guess what cars they are going into? When your car now weighs 30-50% less, it will require a smaller engine. Smaller engine = less production costs. All that and better fuel economy with equal or similar performance. First the i3, etc., then next the MINI's I'm willing to bet.
They are taking a big gamble and technological step forward. It will be interesting to see if/when it pays off.