An all new Riviera for 1966, with major restyling changes and a sleek new body that started a new generation for the Riviera. The headlights were again horizontally paired and moved back in the grille, and retracted above the grille when not in use. Enhancing the clean sleek lines the vent windows were now gone and the roof and rear deck gained fastback like styling. The hood was made longer and was reportedly the longest ever on a car yet, and the taillights were redesigned. On the performance side unfortunately the GS lost its two carb option and the 401 engine was dropped, so the 425, 340 hp became the only factory engine choice. The restyle was an instant success for Buick and sales rose to 45,348 models produced.

An interesting note is that there are about 200 motors that had the dual carb option that were dealer installed!