According to the UK's Autocar and China's Car News, the MG5 sedan will use not only the platform of the Roewe 350 - as does the hatch - but also elements of its styling.
The Roewe 350 made its production debut in 2010, and around the same time, GM and SAIC confirmed plans for a jointly-developed engine family and a new dual-clutch automatic transmission.
The dual-clutch auto has yet to debut in a production model, and little has been announced about the engines. Reports earlier this year however point to a trio of 1.0, 1.4 and 1.5 turbocharged petrol engines.
Those same reports suggested that two dual-clutch autos are in the works: one a wet unit capable of handling up to 360Nm of torque, the other a dry version capable of handling 225Nm.
These latest reports suggest the MG5 sedan will be the first to get the new technologies.
As for GM models, we might expect to see versions of the new engines and transmissions in the next-generation Cruze, which has been spied testing in recent months.