A 1970 Buick GSX built and finished as one of Buick’s own factory show cars helped convince General Motors to greenlight the model at all. In this Muscle Car of the Week episode, owner Brad Conley walks through his Stage 1-equipped GSX at the 2018 Muscle Car and Corvette Nationals – a car with a documented pre-production identity shared by only a handful of surviving GSXs. See the full story, specs, and auction context inside.