U.S. industrywide retail auto sales declined about 33 percent in the first 16 days of April compared to a year ago, but the market shows some signs of stabilizing, according to J.D. Power and Associates, an influential industry tracking service.

New vehicle retail sales are expected to come in at 668,000 units, which represent a seasonally adjusted annualized rate of 7.8 million units, the forecasting firm said.