As GM sought to refine its Harley Earl-based designs that had brought so much success in the 1950s, new design chief Bill Mitchell coined the phrase “knife edge design.” In the vein of Chevrolet’s Corvette Stingray, the groundbreaking Buick Rivera of 1963 brilliantly took the design philosophy a step further. Sharp creases and angular transitions coupled with elegant yet sporting proportions made the Riviera one of the finest GM designs of the decade. For the 1965 model year, the headlamps were tucked behind vertical retractable clamshells, and the Gran Sport performance option was added to less than 10% of the year’s production. Gran Sports boasted a 0-60 time around 7 seconds and a 130 mph top speed. This splendid Riviera Gran Sport received a professional restoration several years ago in its original colors, and the 425 CID Nailhead engine and GS-spec transmission are stated by the consignor to be original to the car. In recent years the Riviera has resided in California as part of a respected collection of postwar American cars, and it has received expert upkeep and care. In light of its formidable performance, rare specification, beautiful presentation, and status as a 1960s icon, this classic from Flint is a sophisticated choice for local car shows, further museum display, spirited jaunts, or all of the above.