Instead of duplicating engineering work from one country to the next, GM's worldwide units now share basic components and work together to design vehicles that with a few tweaks can be sold anywhere in the world.
After modeling GM against Ford on a 11.5 million car year, followed by 12.5 million and eventually 16 million units, GM's market valuation comes in a touch cheaper than Ford but that assumes they hold market share which is not a given.