GM followed Ford’s lead in concluding that SUVs are quickly dropping in popularity, with production line cutbacks that put the iconic Hummer at risk. GM’s Rick Wagoner told shareholders that the market changes in gas prices and car trends are not temporary but structural. In other words, here to stay.

As a result, he explained, GM would be closing four SUV and truck factories, including two in the U.S. GM plans to throw its effort into getting its plug-in, the Chevy Volt, on the market. The Volt has been in development since 2001. Wagoner also explained that the future of the Hummer, the civilian version of a military tank, is unclear and that GM is considering whether Hummer is still within the image the company wants its brand to project.

Wagoner’s comments were not only significant because of what they mean for automakers, indicate that carmakers are coming to terms with the idea that price changes are supply-side and long-term.