Christmas arrived on schedule for the U.S. auto industry as a spurt of sales put the wrapping on a surprisingly successful year. Analysts predicted that sales in December could hit a seasonally-adjusted rate of 17 million, which would be the first month at that rate in nearly six years. That would push 2013 sales up to a robust 15.7 million units.

Welcome as they were, surging sales weren’t the biggest news of the year. Detroit celebrated when General Motors (GM, Fortune 500) made Mary Barra the auto industry’s first female CEO, then held its breath while Ford (F, Fortune 500) CEO Alan Mulally dithered over a move to Seattle and Microsoft. The old Big Three, complaining about straining available production capacity, made plans to expand and hire. Tesla (TSLA) fired up electric car sales and refused to play by industry’s rules, while Google (GOOG, Fortune 500) pioneered a car that drives itself.

There were reversals too. Sales of electric vehicles suffered as gas prices leveled off and then fell. Suzuki wound down its presence in the U.S. market, and Volvo looked none too healthy. Sales in China — now the world’s largest auto market — slowed, and Europe remained deep in a slump, its fundamental overcapacity problems unsolved.

Here are some of the year’s pinnacles and potholes: