 Economists project the average rate will ease to the mid to low 6% range by the end of the year. I'm Alex Vega. U.S. auto sales are expected to slow during the second half of the year. Erin Real has that. According to Cox Automotive, vehicle inventory levels are growing and incentives are increasing. Experts believe that the second half of the year is going to be a tough one for automakers due to growing uncertainty around the economy.