General Motors was not in the best of shape when Roger Smith became Chairman and CEO in 1981. When he retired in 1990, the corporation was in worse shape, in part due to Smith's many unfortunate decisions. This is not to say that Smith's ideas were totally bizarre; in a number of cases he was simply going along with conventional management wisdom at the time. One such item was to rely heavily on high-technology solutions. Another was to adopt Japanese production practices. A major consequence was the launching of what proved to be an entirely unnecessary new make of car, the Saturn.
The Wikipedia entry on Saturn is here and the entry on the first Saturn production model is here. The publicized concept was that the Saturn was to be a hi-tech Japanese car-beater, but by the time Saturns reached showroom floors in Fall 1990, there was little in the way of hi-tech to be found. The most radical feature was the use of fiberglass body panels attached to a metal cage. The selling point was that those panels could easily be repaired or replaced. Another selling point was that Saturns had a fixed sales price, this to eliminate buyers haggling with dealers, a sore point for most car buyers. I never considered buying a Saturn, though I test-drove one of the early ones once, so I'm not sure how trade-in prices were handled. Unless some fixed amount for each potential trade-in was set, the result would be that Saturn dealers could bargain on the trade-in value. Readers who traded a car in when buying a Saturn are urged to tell how that was done in Comments.
Saturn sales were never as strong as expected, and eventually new models based on German Opels were introduced. Before the brand was killed in 2010, Saturns had become re-badged versions of other General Motors cars; whatever uniqueness the brand had possessed was gone.
Shown above are the initial and final versions of the Saturn. From a small Japan-fighter the marque evolved to include large crossover SUVs sharing bodies with the GMC Acadia.