Bearing the cloverleaf emblem and name that identify the brand’s fastest and most powerful model variants, the forthcoming Alfa Romeo Giulia Quadrifoglio (alfaromeousa.com) was introduced in Italy in June and is expected to arrive in the United States in 2016. According to Alfa Romeo, the sedan posted the fastest lap time ever for a four-door production car at the Nürburgring, the racetrack in Germany that serves as a proving ground for high-performance vehicles. The Giulia Quadrifoglio is powered by a 505 hp biturbo V-6 that enables a zero-to-60-mph time of 3.8 seconds. It will be the first Alfa Romeo sedan sold in the United States in 20 years. The company has yet to announce the car’s price.