I read recently that for the first time in history, the percentage of people in the US who drive, as well as the number of cars on the road, is falling. Plus, the US is now behind a lot of other countries in its car/people ratio. I think we are now 16th. (# 1 is Luxembourg, which is small, densely populated, and very affluent)
So, GM must be worried. Many people aren't getting their licenses in high school, and apparently, aren't so eager to start driving.