Total annual sales were 17.21 million in 2018, up slightly from 17.14 million in 2017.
So 2018 was the fourth best year on record after 2016, 2015, and 2000.
Click on graph for larger image.
This graph shows annual light vehicle sales since 1976. Source: BEA.
Sales for 2018 were the fourth best ever.
The second graph shows light vehicle sales since the BEA started keeping data in 1967.
This was a weak start to 2019, but a small decline in sales this year isn't a concern - I think sales will move mostly sideways at near record levels.
This means the economic boost from increasing auto sales is over (from the bottom in 2009, auto sales boosted growth every year through 2016).