It looks like GM had some good news and some bad news for the Chevy Volt to end 2011 with. As Autoblog Green reports, the plug-in vehicle saw its best ever month in December with 1,529 cars sold, bringing its total sales for the year to 7,671. That still wasn't enough to pull ahead of the Leaf electric vehicle in sales for the year, however, as Nissan managed to move a total of 9,674 units despite falling a bit short in December with just 954 cars sold. Both of those numbers are off the automakers' targets for their respective vehicles, though, with Nissan just a bit short of its 10,000-unit goal, and GM well off its original aim of 10,000-12,000 units sold. Unfortunately for GM, 2012 got off to a start with a few new headaches for the Volt.