GM released a teaser with the 2013 Cadillac ATS, a premium sport sedan which will mark the automaker’s lineup expansion from 2012 when the car will enter the market.
With production scheduled to begin next summer at the Lansing Grand River plant in Michigan, the 2013 Cadillac ATS is expected to enter the automotive arena as a competitor against the BMW 3 Series, the Mercedes C Class and the Audi A4.
Mark Reuss, President of GM North America said that "We have
extensively and exhaustively studied the competitive segment, and we
have benchmarked the best. And when this car comes out, that will be
readily apparent."    
There are no details regarding powertrain options but the 2013 Cadillac ATS is most likely going to be offered with a 4-cylinder turbocharged engine, with power being sent to the rear axle.

Source: GM