U.S. auto sales peaked at 17 million in 2005, when Detroit's automakers were much bigger and overproduced cars that they were forced to discount heavily. Sales could eventually reach that level again around 2018, said Schuster, because of 70 million so-called millennials born between 1981 and 2000 who need to set up households and buy cars.
Other trends emerged in 2011. Many people bought smaller vehicles as gas prices hit a record average of $3.53 per gallon. Fuel-efficient compact cars, which have been vastly improved by automakers, are likely to unseat the midsize sedan as America's favorite passenger car for the first time in 20 years.
At the other extreme, pickups rebounded as businesses started to replace older trucks. Sales for the year were expected to rise 11 percent, and Ford's F-Series will remain the country's top-selling model, a title it has held for more than three decades.
For much of the year, U.S.-based automakers took advantage of Japanese car shortages to increase sales, especially in the compact car segment normally dominated by the Honda Civic and Toyota Corolla. Japanese companies ran short of popular models after an earthquake and tsunami disrupted production in Japan in March.
Ford, GM and Chrysler saw their combined share of the U.S. market rise by 200,000 cars and trucks between the end of 2010 and November, 2011. The Detroit Three's market share rose from 45.1 percent last year to 47 percent through November of last year. At the same time, Honda's share fell 1.6 percentage points to 9 percent, while Toyota's dropped 2.5 percentage points to 12.7 percent.
Schuster expects Japanese carmakers to take back some of the sales they lost.
Geoff Pohanka, who runs a chain of car dealers in the Washington area, said his December has been strong, thanks especially to the restocking of cars at his Honda and Toyota showrooms. He predicts Japanese car companies will offer incentives to regain lost sales.