Edmunds forecasts that 1,376,253 new cars and trucks will be sold in the U.S. in November for an estimated seasonally adjusted annual rate (SAAR) of 17.3 million. This reflects a 1.3 percent increase in sales from October 2018, but a 1.3 percent decrease from November 2017. Edmunds analysts note that this month marks the first drop since 2009 in November sales, which have grown year over year in part due to increasing demand following the recession, and in part due to November becoming a bigger sales month thanks to automakers and dealers capitalizing on Black Friday.

"Retailers have been pushing Black Friday car deals through the entire month of November, so unless they decide to pull out all the stops in the 11th hour, this is likely going to be the first time we see November sales take a dip in nearly a decade," said Jeremy Acevedo, Edmunds' manager of industry analysis. "Although sales remain at a healthy level, factors such as increasing market saturation, rising transaction prices and elevated interest rates continue to create headwinds for the industry overall. November's sales slowdown signifies a new normal that we can expect through at least the end of 2018, and likely into 2019."

Edmunds estimates that retail SAAR will come in at 14.3 million vehicles in November 2018, with fleet transactions accounting for 17.2 percent of total sales. An estimated 3.0 million used vehicles will be sold in November 2018, for a SAAR of 39.8 million (compared to 3.3 million —  or a SAAR of 39.6 million —  in October).

For the first time, estimates for Tesla are included in the Edmunds retail SAAR calculations, volume forecasts and market share estimates for November. Edmunds analysts note that Tesla's increasing impact on the market makes it necessary to include these figures as part of the overall industry sales picture, and as a result will continue to include them monthly moving forward.