Light vehicle sales in 2019 were revised down slightly to 16.95 million, down 1.5% from 17.21 million in 2018.
This graph shows light vehicle sales since 2006 from the BEA (blue) and an estimate for January 2020 (red).
A small decline in sales last 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).
Note: dashed line is current estimated sales rate of 16.84 million SAAR.
Sales have been generally decreasing slightly, but are still at a high level.