Continued economic improvement, low interest rates and cheap gasoline will help new-vehicle sales rise more than 3% to nearly 17 million units next year, the most since 2005, according to forecasts from the National Automobile Dealers Association . Automotive News reported that NADA sees U.S. new vehicle sales growing to 16.94 million units in 2015 from a projected 16.4 million this year, as U.S. gross domestic product grows 3.1%, compared with an estimated 2.1% this year.