Total car sales tend to lead the overall economic cycle at the peak (see the chart below; double-click to enlarge). There are reasons proffered for this current downshift: people are holding on to their cars longer; millennials aren't buying cars. Yet varying explanations for falling car sales are produced every cycle. As you can see from the chart, it's a big decline.
Add in the rising cash rate from the Fed; an impending reversal of QE (quantitative easing) to QT (quantitative tightening) as the Fed starts to sell down its bloated holdings of long term-debt bought to provide stimulus over the last 7 years; and consumer weariness, and it's looks quite likely there will be a recession. When? Can't tell yet. But it does raise some question marks over the boom on Wall Street.
Disclaimer. After nearly 40 years managing money for some of the largest life offices and investment managers in the world, I think I have something to offer. These days I'm retired, and I can't by law give you advice. While I do make mistakes, I try hard to do my analysis thoroughly, and to make sure my data are correct (old habits die hard!) Also, don't ask me why I called it "Volewica". It's too late, now.
BTW, clicking on most charts will produce the original-sized, i.e., bigger version.