The 6-Series is BMW's most exclusive 2-door model series. With a base price of over $90,000, this four passenger convertible model is almost without equal. BMW's German competitors offer convertible roadsters in this price range, but the 6-Series manages to keep a tight but usable rear seat. There are several four-passenger convertibles for less money including BMW's own 3-Series convertible. The convertible is a power-retractable soft top that opens in 19 seconds and closes in 24 seconds. The 650i equips a 400-bhp 4.4l V8 under the hood which is paired with an either a six-speed manual or eight-speed automatic. The 640i model pairs BMW's 3.0L inline six with an eight-speed automatic to achieve an impressive EPA rating of 21 / 31 (city / highway). BMW claims that the 650i convertible can sprint to 60MPH in 4.9s. Like other modern BMW models, the 6-Series is chock full of exotic materials and cutting-edge driving aids. Owners can brag about the standard 10.2-inch center screen or the 20-way adjustable seats (650i).