Not a car guy. (General Motors)

Industry by industry, women have broken into C-suites previously occupied only by men. Tech may be male-dominated, but at least it's got Virginia Rometty and Marissa Mayer. Aerospace equally so, but at least Lockheed Martin installed Marillyn Hewson in the top spot earlier this year.

The auto industry had been a holdout, however, overseas as well as in the United States. That is until Tuesday, when, right after the news that the U.S. Treasury had sold the last of its General Motors stock, the company announced it had chosen 30-year veteran Mary Barra as its first female chief executive -- and the entire sector's first, as well.

Of course, Barra has lots to recommend her besides her gender. An electrical engineer by training, she's served in most departments at GM, most recently as chief product officer, where she's taken on the company's high cost structure for making stuff that isn't necessarily better than its competition. Before that, as head of human resources, she attacked the reams of red tape around what people could and couldn't do while at work (including wearing jeans).

When asked how she thinks about her gender in the automotive context, or even about the mark she's personally made on GM's products, Barra tends to demur, talking about the importance of her team and all the other women at the company. But she doesn't need to talk about being a woman in order for it to have an impact, both for the image it projects to the world and the tone it sets inside the company. A Bloomberg Businessweek profile had this charming detail:

When she ended a recent meeting at 4 p.m. to pick up her daughter, others thanked her for it. “One of the guys said to me, ‘I’m so glad you said that because I’m meeting my wife.’ A lot of women’s issues are men’s issues as well.”