General Motors said today it is investing $163.2 million in its operation in Flint and Bay City, Michigan and Defiance, Ohio, to support engine production of the Chevy Volt, Chevy Cruze, and a new Chevy small car to be built in the US GM said the investment will protect 184 jobs at the three sites.  GM noted that the announcement today brings the total of new US investment to more than $3.3 billion, which has created or retained more than 8,000 jobs since July 2009.