Today on Green Car Reports: Hamburg, Germany, aims for car-free streets in 20 years, soaring demand could lead to a doubling of U.S. Nissan Leaf electric-car production, and the Mazda 6 diesel sedan will be further delayed, according to the company. All this and more on Green Car Reports.

The Volkswagen Passat BlueMotion Concept--a high-mpg version of VW's midsize sedan--is set to debut at the 2014 Detroit Auto Show.

The 2014 Nissan Leaf electric car gets an 84-mile range and standard RearView monitor.

Tesla Motors' Supercharger quick charging network is expanding beyond the coasts.

New-car average fuel economy rose to 24.8 mpg in 2013.

Hamburg, Germany aims for car-less streets in 20 years.

Elio Motors takes another step toward building its 3-wheeler in an ex-GM assembly plant.

With demand soaring, U.S. Nissan Leaf production could double this year.

Will the 40-mpg Mitsubishi Mirage minicar add a sedan model for 2015?

The Mazda 6 diesel sedan will be delayed further, the company says.

Learn the 10 new rules for buying a new car.

And, finally, the 2015 Audi Q3 compact crossover is revealed.

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