Ah Saturn, the car of unemployed psych majors.
Saturn started out as kind of a pie-in-the-sky dream of GM, a truely "different" kind of car company (just like their tag line). Think of Saturn as what Scion is to Toyota. GM tried to go all out and build a car brand that could compete with imports at the time. GM kind of know that if they built their new car at any of the established factories, it would be a rattle-trap POS because it would have the same GM quality (oxymoron) as their other cars. Think hard about what the early 1990s Luminas and Cavaliers used to be like.
To get a fresh start GM built the Saturn factory in Spring Hill, Tennessee, and very remarkably, didn't have UAW involvement with this experiment. Saturn build their initial models (the SL, SC, and SW) off a dedicated platform with a dedicated engine. Saturn used those plastic body side panels to keep the car lightweight, resist dents, and in theory they could change the bodywork very easily. In practice, Saturn built the same 3 cars almost unchanged for a decade. The dealership network had their no-haggle stress free atmosphere, which is really the only thing that sold the cars because imports were still better despite the good intentions of GM.
There are a few reasons why Saturn never really caught on as a car company, but the reason I suspect as being the greatest is the lack of later support from GM. A car brand really can't be built in short time like the method that GM tried to use. Scion works for Toyota because their cars are built off of current production platforms - rebadged cars that are already built and sold in other parts of the world. GM built Saturns on a dedicated platform - expensive and long term in development because no other cars use it. It was hard for Saturn to come up with money to update the platform of their cars because the sales volume never was high enough to have the income to devote to R&D. Build a few more cars off the same platform as a different brand, and then companies can share R&D. Saturn started out small, and then GM pretty much didn't give much financial support - especially not help developing future products in the time span that they were needed the most. That's like telling a 4-year-old to get a job and make it on their own.
Now? Saturn pretty much just exists as a brand of big GM. The dealerships are the only thing left. The cars are now rebadged GM products made at other plants. The new ION that replaced the S-series is merely a Chevy Cobalt under the skin, and Car & Driver described the ION as "one rickety bastard of a car" in their long term test. The VUE is just a GM SUV platform that is shared with a few other products. The only selling points for that is the Honda V-6 engine, and the new mild hybrid that got a good review from the Chicago Tribune as being one of a scant few vehicles that hit it's EPA fuel economy rating in testing. The Sky roadster looks decent, and we'll see how the new Aura does in sales. But buying a Saturn now is like buying a Pontiac or a Chevy. No matter what model you get it will simply be another GM product, nothing special or different with their cars.