Certainly not in keeping with Buick’s traditional image, the ’70 BUICK STAGE I GS-455 – FIRST ADULT SUPERCAR catapulted the Flint automaker into the heat of the battle for Supercar supremacy. The Skylark GS-455, in 360 horsepower Stage I trim, was the industry’s first “adult” Supercar. It was a powerful, high-quality, well-balanced midsize coupe (or convertible) with superb ride and handling qualities. Yet it was almost invisible compared with competitive offerings like the SS Chevelle,...