The 1966 Impala SS was facelifted with a revised grille and new rectangular taillights that replaced the triple round units. A chrome beltline strip shared with regular Impalas was added in response to complaints about door dings on the clean-lined 1965s. Inside were new Strato bucket seats with thinner and higher seat backs, and a center console with an optional gauge package available. Sales of the 1966 Impala SS dropped by more than 50% to around 117,000 units; this was mainly due to the sport/performance car market switching from full-sized models to intermediates (including Chevrolet's own Chevelle SS396 and Pontiac GTO), along with the emerging market for the even smaller pony car market created by the Ford Mustang in 1964 that Chevrolet would respond to with the Camaro for 1967.