There were a few 2011's sold as "new" from inventory. GM got their nose out of joint about it. Criswell was the dealer, in Maryland.
(repetitive but different publications)http://jalopnik.com/5815228/chevy-deale ... police-carhttp://www.automotive.com/news/2012-che ... dan-50073/http://www.motortrend.com/news/chevy-ca ... ivic-duty/
There have been other PPV's sold new from aged inventory since the 2011's snuck out, but only after GM authorized the sale of new PPV's to "retail" customers that did not appear to have any qualified (LE/government) buyers. This may have happened more than once, but it's not something that gets much publicity.
Some of us managed to buy a PPV that was never in service, but was being sold as "used", because the dealer had the smarts to do an internal ownership transfer, then offer them up as used for less than sticker--my 2011 sat at the dealer for over a year before I bought it in Nov 2012--test drive odometer reading was 23 miles, but the warranty had started 7/30/2012. The maneuver allowed the dealer to get around the GM restriction on sale (as new cars) to unauthorized (civilian) customers.
All I can suggest is to find a helpful dealer that can search for inventory, then push the issue--GM police fleet managers don't take too kindly to selling these cars outside of their intended customer base, so I'll just say good luck if you find a way to get one!