The BMW 650i returns for 2007 all but unchanged from 2006. It delivers excellent performance, brilliant handling and that arrow-like stability that defines BMW. Available in coupe and convertible body styles, the BMW 650i is a premium grand touring car. It comes with a 360-hp V8 and a choice of three transmissions.

Changes to the 650i for 2007 are few, mostly limited to creature comforts, including an iPod interface, optional Pearl leather upholstery and other leather accents. New also is a tire pressure monitor that warns the driver when a tire begins to lose air.

The BMW M6 Coupe, introduced late in the 2006 model year, returns for 2007. The M6 boasts a 500-hp V10, seven-speed sequential gearbox, M-tuned suspension and electronic stability control, special wheels, Z-rated tires, and distinctive interior and exterior styling.

New for 2007 is the M6 Convertible, a first in the long and storied history of 6 Series BMWs. Like the 650i Convertible, the M6 Convertible is identical to its coupe counterpart, other than the one-button, powered folding top.

For 2007, the M6 gets a tire pressure monitor. Late-model 2007 M6s will be available with a six-speed manual transmission as a no-cost alternative to the standard seven-speed Sequential Manual Gearbox. The SMG substitutes an electronically operated clutch for the regular clutch pedal, and we don't love it. We recommend getting the six-speed manual.

Both coupes and convertibles have a back seat that can fit small people in a pinch, but are really intended to move two people and their belongings in high comfort, style and safety. The 650i is more luxurious than the Z4, and delivers higher performance, more agility and sportier styling than the 5 Series sports sedans.

The M6 sacrifices some of the Grand Touring comforts of the 650i in favor of a more aggressive handling package and stratospheric acceleration performance. At the same time, the M6, and especially its sequential manual transmission, takes the marque in a direction purists find distressing, increasingly transferring control of the car from its driver to its super-sophisticated electronics.

More generally, and more generously, BMW's corporate design themes, panned by many in recent years, seem to fit better on the long, low 6 Series. And an intricate top design blesses the convertible with the same, nicely integrated, fastback-like profile as the coupe.