Having been unleashed with a series of angry Trump tweets, the outpouring of carmarker investments in the US has turned into a veritable torrent, and just hours after GM announced it would invest $1 billion in new US factories, adding 1,000 jobs, Korea’s Hyundai Motor Group said it also plans to lift U.S. investment by 50% to $3.1 billion over five years and may build a new plant there.