2018 Chevy Sonic caught testing in The Motor City

Despite its role as the entry point into Chevrolet's lineup of sedans in America, the Sonic can be a fun little urban runabout in the same vein as the Ford Fiesta and Honda Fit. It's also impressively fuel efficient. Suffice it to say, then, that the Sonic is way better than the Aveo it replaces. And, as you can see from these spy shots, the next version of the Sonic is currently being tested in the wintry climes of Detroit, Michigan.

The 2018 Chevy Sonic will be based on an updated Gamma platform that will be shared with the all-electric Chevy Bolt. In place of that's car electric motor and massive battery pack will be either a naturally aspirated four-cylinder or small turbocharged engine. Spy shooters suggest a three-cylinder engine is also a possibility.

While it's clear from these spy photos that the development of the next Sonic is well underway, nobody is quite sure where it will be built. Last October, Autoblog reported that 500 workers at GM's production facility in Orion Township were being laid off due in part to slow sales of the Sonic – you can thank the growing popularity of crossovers for that – and that plant is now being retooled for production of the Bolt. It's entirely possible that GM has decided to move production of the Chevy Sonic to Mexico, which would allow it to build a more profitable vehicle at Orion Township alongside the Bolt.