The Nissan Leaf was expected to popularize electric vehicles, but relatively modest sales in 2011 left some people questioning just how successful the car could be. However, the automaker is poised to unveil a new and improved version of the Leaf later this year with the hope of doubling sales in 2012, The Detroit News reports.

Many of the changes to the Leaf will be in its appearance. Although it outsold General Motors' electric option, the Chevrolet Volt, in 2011, the Volt gained significant ground in February. The reason, some think, is that the Volt offers a sleeker, leather interior while the Leaf's look reflects its eco-friendly message. The manufacturer sensed the displeasure from customers, and has made the appropriate changes.

"We were like, 'Ah, let's do the clean, green recycled materials,'" Mark Perry, the director of product and advanced planning for Nissan Americas, told the newspaper. "People want a dark interior, so we're to give them a dark interior, too."

Just how popular the Leaf ends up being remains to be seen. Only recently did it become available to drivers in all 50 states, but its first months have not been without a few snags. For instance, some drivers report that the Leaf's range is limited in cold weather regardless of whether the heat is turned on. Still, Nissan believes that electric is the way of the future, and is expected to release an electric version of its luxury brand Infiniti later this year.

Although it will still be quite some time until electric vehicles rule the highway, you can still purchase an eco-friendly and fuel-efficient used car at New Jersey State Auto Auction. With a wide variety of makes and models you'll be sure to find the right car for you.