General Motors Co. is well on its way to adding more than 650,000-square-feet to its Alexis Road transmission plant, though company officials have been very tight-lipped on their plans for the Toledo facility. 

GM announced in late 2016 it would invest $668 million there to prepare the factory for an unspecified new product line, upping investments in the plant to more than $1 billion since 2011. 

A company spokesman declined to comment further last week on the new product line. 

The plant, which employs about 2,000, makes 6-speed and 8-speed rear-wheel-drive transmissions and 6-speed front-wheel-drive transmissions for GM trucks, sedans, and sports cars.

First Published May 21, 2017, 4:00 a.m.