Starting production of the all-electric Leaf in Tennessee helped Nissan sell more Leafs in the US in March 2013 than in any other month. April wasn't quite as sunny, but the 1,937 Leafs sold last month were still good enough for second place. Ever. It also represents a 423.5 percent year-over-year increase and Nissan says that, so far in 2013, Leaf sales are up 160.4 percent compared to the same time frame in 2012. April also marked the second month in a row that the Leaf beat the Chevrolet Volt. The two vehicles use different drivetrains, but Nissan, at least, considers the other popular plug-in its competition.

It's not that General Motors had a bad month. The 1,306 Volts sold last month were roughly in line with March and February (but it's a downward trending line, with 1,626 sold in February and 1,478 in March). 2013 April Volt sales were down 10.7 percent from April 2012 but, year-to-date, Volt sales are up 3.2 percent in 2013 compared to 2012.

As always, we'll have our detailed write-up of last month's green car sales up soon. For now, discuss.