The cars are, at the very least, being assembled in Springfield. I don't know how many parts will actually be built there; I know at the very least the body shells are going to be imported, but I don't know what else. The MBTA's requirements aren't as stringent as the "Buy American" policy that is used when the Feds put money towards something, so it doesn't all have to be made in-country. I assume they will ship in whatever requires a significant extra capital investment to build the machinery to produce the part, since they do already have facilities to do such... in China. It'll be a cost comparison to how much it costs to make it in China and import it, compared to the initial capital investment to build the capabilities to build whatever part and the cost to produce it in the U.S; I can't imagine that'll leave anything major being built in Springfield.
I'm not going to be so cynical to assume the cars will be absolute garbage because of that, since it is possible to get high quality products out of China, but... it's a wild, wild west for quality out there because of the lack of standards, so it's anyone's guess how it'll work out. Quality products only happen when a company is dedicated enough to try and impose and enforce high(er) standards on their products. Hopefully CNA understands that they'll doom their ability to get more American contracts, and therefore waste their own investments into this factory, if they screw up the T's contract.
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