One problem related to transmission not go into gear has been reported for the 2007 Saturn ION. The most recently reported issues are listed below.
As I was driving along a city street last autumn, the transmission started shifting with a noticable jerk each time it went into another gear. This is an automatic transmission. When I came to a stop light I put the car into park. When I put the car back into gear, there was an even stronger jerk. The jerking kept on each time the car shifted. At the next light I turned the car off during the red light and then turned it on when the light turned green. The problem continued, so I went straight to an auto repair shop. They were busy so I had to wait awhile, and then it took me awile to explain the problem. When the technician went out to see what the problem was, the problem was gone. Isn't that soooo typical. This last summer, the same thing happened. This time I went home and let the car sit there for 15 to 20 minutes. The problem was gone again. My fear is that this could happen at highway speed and god only knows what could happen then.