A question I have from the article is regarding the timing. AFAIK, Dart and 200 are to cease production within the next 6 to 12 months. The capacity at Magna's plant in Graz is spoken for. Is there enough time for Magna to get another plant up and running without extended suspension of production of those two models?
With the factory changeovers coming so soon, I would imagine that the plant where they will be built must already be in existence, a deal must already be made, and plans must be in the process of finalization.
The Mitsubishi plant in Normal, IL, has been sold, so that's off the table.
The Mazda plant in Mexico seems to have the capacity but it is not tooled to produce CUSW vehicles AFAIK (maybe the plant is flexible enough that modifications can be made quickly to prepare it for the Dart and 200?).
The Tofas plant in Turkey is producing a wide range of vehicles, including the Doblo and its variants, and the Tipo and its variants. I don't know this for a fact, but I would imagine that it is at or near capacity. Also, like the Mazda plant, it is not, AFAIK, tooled for the Dart and 200's CUSW platform. All of its vehicles are on the "small"/SCCS/SUSW platform(s).
AFAIK, once TNAP and SHAP have been retooled for the Wrangler and Ram, respectively, there will be only two plants in the world with the CUSW tooling: Belvidere, and FCA/GAC's Changsha plant in China (unless the related Giuietta's plant in Cassino is capable of running CUSW also-- but we know that at least the Giulia, Stelvio, and Dodge D-CUV will be produced there, and that the "C-EVO" Giulietta will be discontinued within the next two years or so, so that plant seems unlikely).
Changsha truly seems like the most obvious choice. The tooling is in place. It has excess capacity. It already produces a modified version of the Dart's body as the Fiat Viaggio. As of the May 2014 product plan, it was planned to produce a CUSW Fiat D-sedan. In late 2014, a deal was announced that FCA/GAC would produce an unspecified Chrysler brand vehicle.
I suspect that this is a done deal and that FCA is simply waiting until the last minute to announce it because they are aware of the flack that they will take for moving production from the US to China. Luckily for them, GM was the first (but likely not the last) major automaker to make such an announcement.