Remaining Government shares were sold to someone directly.
The price action on GM over the last several weeks has been positive. I think, if the remaining shares were sold into the market, the share price would be lower than the current quote. It is possible that GM repurchased the remaining shares.
I also think that GM management has the ability to push the share price much higher, and, going forward, they want to take the very high share price and jam it down all the throats of those people who had referred to GM as Government motors.
Just a note for those who wish GM ill will:
Don't worry, if you don't like, or want to buy GM cars or trucks, they will still do very, very well.
Stock price goes MUCH higher, as you keep hating GM!!