It's the kind of question that makes every CEO roll his eyes.

In effect, it translated to: Your sales of one model last month were lousy, so is that car a failure in the market?

But if the model is the Nissan Leaf, the first battery electric vehicle sold in volume in the U.S. (and around the world), the question takes on added resonance.

It referred to last month's U.S. sales of plug-in cars. Nissan sold 579 Leafs, while Chevrolet sold a whopping 2,289 Volts. That put total Volt sales ahead of Leaf sales for the first time since the two cars went on sale in December 2010.

At this morning's New York Auto Show keynote, Nissan CEO Carlos Ghosn effectively rebuked the questioner.

"Don't take one or two months' sales results in one or two markets," he said, "to make conclusions on this important segment of the market."

Ghosn reaffirmed his prediction that plug-in cars would be 10 percent of the global vehicle market by 2020.

He did, however, add a new qualification: " the markets where those cars are available."

MORE DETAIL: Electric Cars ARE Coming, But It Will Be Slow: Why Is This So Hard To Grasp?

He acknowledged that global Leaf sales--roughly 20,000 globally in 2011, and 27,000 as of the end of last month--were lower than the company had predicted before the car launched.

He pointed, however, to both the March earthquake and tsunami that severely disrupted the Japanese auto industry for several months last year, and what he called a "man-made disaster."

That would be the yen-dollar exchange rate, which has fallen from 110 yen to the dollar to 76 yen--making cars built in Japan far more expensive in the U.S.

Carlos Ghosn

Carlos Ghosn

Ghosn said Leaf sales will soar once U.S. production of the cars begins in Smyrna, Tennessee. He said that would happen "this summer," though a Nissan representative confirmed that battery production starts in September and Job One for U.S.-built 2013 Nissan Leaf models is scheduled for this December.

That "localization" will let Nissan reduce Leaf costs considerably, Ghosn said, though he gave no details on possible price cuts for the 2013 models that will roll off the lines in Tennessee.

He noted proudly that Nissan has had "no quality problems" with the Leafs sold in the U.S., Japan, and Europe, "which was our Number One goal."

And he predicted that as oil prices to continue to rise with global economic recovery, further driving up gasoline cost, environmental reasons won't be the only ones driving buyers toward Leafs.

"It will be the economics too," Ghosn said, "that get people to use more electricity as fuel."


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