This was the year that U.S. auto sales were supposed to tank after six straight year-over-year increases. Like Brexit and Hillary Clinton's presumed cakewalk to the White House, auto sales in 2016 have confounded the experts.

Sales for the month of November came in strong for General Motors  (GM) , Toyota Motor  (TM) and Ford Motor   (F) , while Fiat Chrysler Automobiles N.V. (FCAU) posted a big decline. Overall, the industry is expected to register a seasonally-adjusted average rate (SAAR) of 17.9 million vehicles for the month or close to it.

Just as pollsters and journalists clearly underestimated U.S. voter disappointment with establishments of both political parties this election year, analysts may have underestimated U.S. consumer optimism -- an important indicator that signals the willingness to finance a new vehicle or a new home.

And this unexpected trend may continue for a while: Mustafa Mohatarem, GM chief economist, said "the U.S. auto industry is well positioned for sales to continue at or near record levels into 2017."

Automakers have been boosting discounts and financial incentives, hoping to stimulate demand and keep sales going. As has been the case all year, sales of crossovers, SUVs and pickups were especially strong, driven by relatively cheap fuel prices. With one month left to go in 2016, a strong December could break last year's record 17.5 million vehicles sold.

GM sales for the month were up 10.2%; Ford's were up 5.1%; Toyota gained 4.3%; Nissan Motor  (NSANY) sales rose 7.5% and Honda Motor  (HMC) sales were up 6.5%. Fiat Chrysler fleet sales were down 42%, leading to a 14% overall decline.

If you liked this article you might like

Your Guide to Making a Lot of Money on the Driverless Car Boom

How to Live Just Like Billionaire Warren Buffett

Driving This Beastly Cadillac CTS Reminded Me That Sexism Is Alive and Well