Ferrari NV unveiled the speediest production car in its history, underscoring its reputation for uncompromising performance even as the Italian manufacturer pushes the limit of how many autos it can sell without losing its allure. The 812 Superfast debuted at the Geneva International Motor Show on Tuesday with a 12-cylinder, 800-horsepower engine that accelerates to 100 kilometers per hour in as little as 2.9 seconds, making it Ferrari’s most powerful production model ever.