The 6 Series coupe is based on the 5 Series sedan and shares its powerful 4.8-liter V8 teamed with a smooth, quick-shifting automatic. An even-faster V10-powered M6 version uses an automated manual or an optional manual transmission. Handling is agile for such a large car. The ride is a little choppy at low speeds, but otherwise it is steady, with good isolation. The luxurious and quiet interior has excellent front seats. The small rear seats are only for short trips. The iDrive driver-interaction system is distracting. A convertible version is available. Reliability has dropped to below average.