A sporty Buick might be emerging from an idled GM plant.

As we begin to learn more information about the deal cooked up between the United Auto Workers and General Motors, rumors have begun swirling that a sport-oriented Buick three-door will be built in the U.S.

For a while now, we've been aware that GM executives in North America are seriously considering rebadging the just-unveiled Opel Astra GTC as a Buick. Now, we have learned that it could be built in the U.S.

GM has said that it plans to build an additional compact car at an unnamed plant in the U.S. in order to satisfy the UAW. Since we know where GM is building its current and upcoming compacts - the Chevrolet Cruze (Lordstown, Ohio), Buick Verano (Orion Township, Michigan) and Cadillac ATS (Lansing, Michigan), it seems almost a given that the next vehicle will be the Astra GTC with a Buick nameplate.

As for where it will be built, GM has committed to reopening its shuttered Spring Hill, Tennessee, plant and it has said that production of the new compact will spur the hiring of an additional 500 workers. Put two and two together and it certainly seems like a sporty Buick could be rolling off the line in Tennessee by early 2013.

GM closed shop at Spring Hill in late 2009 when it transferred production of the Chevrolet Traverse to another facility. The plant, one of GM's newest global facilities, was opened in the early 1990s as the exclusive Saturn plant. It remains the only idled Detroit-brand production facility in the South, a region where foreign carmakers have prospered without unionized workers.