The automakers will report August vehicle sales on Thursday, Sept 1st.

Note:  There were 26 selling days in August, the same as in August 2015.

From WardsAuto: Forecast: U.S. Light Vehicles Sales Weaken in August

A WardsAuto forecast calls for August U.S. light-vehicle sales to reach a 17.4 million-unit seasonally adjusted annual rate, less than like-2015’s 17.7 million and July’s 17.8 million, but ahead of the 17.2 million recorded over the first seven months of this year.
emphasis added

From J.D. Power: August Decline in New-Vehicle Sales Fourth in Last Six Months

The SAAR for total sales is projected at 16.8 million units in August 2016, down from 17.7 million units a year ago.

Vehicle sales are moving more sideways now.