The National Automobile Dealers Association (NADA) forecasts 16.94 million new cars and light trucks will be purchased or leased in the United States in 2015. Rising employment and wages, continued low interest rates and lower gasoline prices all signal an increase in new light-vehicle sales in 2015, according to NADA Chief Economist StevenSzakaly. In order for new car sales to rise above the 17 million unit mark, manufacturers would likely need to ramp-up incentives, and millennial shoppers would need to buy new vehicles in greater numbers than they have over the past several years.Employment and Wages – NADA forecasts that job growth will continue to increase to an average of 242,000 new jobs per month in 2015. Job growth should lead to a small increase in disposable income of approximately 2.5% in 2015.Interest Rates – NADA expects The Federal Reserve to raise interest rates in 2015, but the rate increase will likely be very small. NADA also expects long-term rates on auto loans to rise by 125 to 150 basis points by December 31, 2015, with the rise occurring steadily over the course of the year.Gasoline Prices – Oil and gasoline prices are expected to remain weak through 2015, and lower oil prices typically translate into lower prices at the gas pump for consumers with an increase in household spending on other goods and services.