I first found this site while searching for a reason that my 'Service Engine Soon' light kept coming on. We've had our Saturn for over a year, and use it primarily for commuting; it averages about 33mpg. However, it has some quirky problems that really detract from its overall value.
First, there is the aforementioned engine light. From time to time it will come on just out of the blue, yet every time we take it in, there's no code found. What a waste of money! A few days later the light will just go off.
We have the same problem with the radiator light, even though the reservoir is full.
Occasionally, the car will simply not start. We've replaced the battery, and the starter is fine, but there is some quirky electrical problem that does not permit the ignition to engage. If you try repeatedly to start the car when this happens, eventually it will catch. There's no real rhyme or reason to this.
This is a very cheaply made car with considerable road noise. However, the PARTS to fix it are ridiculously expensive. I am hesitant to rely on it for trips that are outside of our "towing range". But all in all, you get what you paid for. We would not buy another Saturn.