The second-generation Celica was released in August 1977, after an interval of six years and eight months. Like its predecessor, the second-generation Celica shared its platform with the Carina, on which a 2-door coupé or 3-door liftback body was mounted. The body design was undertaken by Calty Design Research, Inc., Toyota's design studio based in North America. The low beltline, wide glass areas, and broad B-pillars (for the liftback) were among its prominent features. The shock-absorbing bumpers, which were employed in the middle of the first generation with high-grade models, changed their material to polyurethane in the second generation. Due to the increasingly stringent emission control, the engines had to be modified to meet the latest 1978 emission standards, which presented a major challenge for high performance engines. Nevertheless, the Celica continued to use the DOHC engine, because it had already become part of Celica's brand identity. In a minor model change in September 1979, the 2000GTV was replaced with the 2000GT Rally model to celebrate the Celica's success in international rallies, and the 1600GT Rally model was added to the line in November. In a facelift in August 1979, the four round headlamps were replaced with rectangular ones.