The 6 Series seats provide excellent support. The 650i base seats are the more accommodating, with the optional sport seats more firm than cushioned but still not as encapsulating as the M6's. Depending on the package, front seats are power-adjustable in either 12 ways or 14 ways (in the M6, either 16 or 18 ways, including seatback bolsters) and combine with a steering wheel that both tilts and telescopes, again with the push of a button, to allow drivers of virtually any stature to find a comfortable, if not perfect fit. All front seats also have BMW's signature, manually extendable thigh support.

The back seats will accommodate pre-adolescents on short trips, but will not work for two couples enjoying a night on the town. Access, though, isn't as difficult as in some cars, as the front seats readily move forward and, thankfully, return to their previous settings. Driver-side memory buttons are on the outboard side of the seat base, a much more convenient placement than in the 7 Series, where they're on the center console and unreachable before climbing into the car.

Interior materials and finish are generally up to standards expected in this price range. The headliner in both coupe and convertible looks and feels rich, and expensive. The standard trim, BMW calls Ruthenium (named for a hard white metal), is a metallic material, and we like the way it looks on the doors and dash. For 2007, a pearl-shade leather is the optional trim for the 650i. Those who prefer a more traditional look can choose either light or dark stained birch wood in the 650i at no charge. The M6 offers Olive Ash as a cost-free alternative to the standard Madeira Walnut. Our M6 came with trim designed to look like carbon fiber, but came off looking like something you'd see in a modified Honda Civic.

A Start button is used to start the 6 Series. The key is an electronic cartridge that slides into a slot on the steering column. Once that's done, the driver simply presses a button on the dash to the right of the steering column to start or stop the engine. That's the cool part. But turning on accessory power requires pressing the button once, then again, and then again, all while consciously keeping your foot away from the brake pedal so the engine doesn't start. James Bond would be in big trouble with this setup.

Comfort Access is an option that takes this keyless concept a step farther. It's proximity-activated, meaning you can simply walk up to the car, open the door, and press the Start button without having to pull the fob out of your pocket or purse. The car will warn you if you try to leave with the key while it's running.

The M6 adds another start-up challenge with its Sequential Manual Gearbox: The SMG has to be in Neutral to start. It has to be in gear when switched off or you get an annoying tone. You may grow to hate that tone, you hear it so frequently. The tone comes on immediately upon starting if you don't have your seatbelt buckled.

The gauge cluster features a large tachometer and speedometer framing an LCD box that displays a wide range of information. The package is crisp and legible and, if you like BMW's familiar orange backlighting, quite attractive. The optional Head-Up Display projects speed, navigational information, cruise control status and other data onto the windshield and can be programmed to show whichever data set the driver chooses. It works well and we find it useful. The M6's HUD is further configurable, offering a minimalist display limited to the essentials of analog-like, LED tachometer, selected gear and road speed.

BMW's iDrive system is used to operate the stereo, climate controls, navigation and other systems. iDrive uses a big knob mounted on the center console to set and adjust the various systems. In effect, it works like the mouse on a personal computer. Functions can be selected by rotating the big iDrive knob to highlight menu options displayed on a monitor in the center stack then pressing it down. Sliding the knob left or right, forward or aft switches menus. The system has been simplified since it was introduced in BMW's 7 Series. A separate button is available that returns directly to the opening menu; and the knob no longer moves diagonally.5

We recommend spending time in the driveway with the owner's manual to master this system. The iDrive has been hated, loved and tolerated. We find it difficult to operate and distracting from the business of driving. It overloads us with choices. Using it for everyday tasks often demands pressing more buttons than with traditional systems. After figuring out how to select AM and FM, then figuring out how to dial in a station, we could not figure out how to preset a button for our favorite radio station. And trying to call up a map was baffling. Owners will figure these things out, of course, and some owners will master iDrive, but we're not fans.

Touch the turn signal lever and the signals blink three times, which is useful when making lane changes but annoying when you change your mind and try to cancel it.

The coupe's trunk is relatively large, with room for two sets of golf clubs. The BMW badge on the rear serves as the trunk latch. The lid pops open fully when a button on the key is pressed, handy when running through the rain with an armload of groceries. Watch where you put those groceries, however, as the trunk lid uses bag-crushing goose-neck hinges; the convertibles use articulated struts, necessary to clear the expandable pouch for the folded top. The coupe has a slightly larger trunk (13 cubic feet) than the convertible (12.4 cubic feet), though the convertible's trunk shrinks (to 10.5 cubic feet) when the top is down due to that expandable pouch. Also, caution is advised when storing anything other than luggage or those golf clubs in the trunk, especially if that anything involves liquid. The space below is full of electronics essential to the car's operation. The first time we lifted the floor cover, it was like watching Darth Vader remove his helmet. The 6 Series cars do not come with spare tires. The 650i models come with run-flat tires, while the M6 comes a temporary repair kit.

Incidental storage is limited. The glove box is nicely finished but not large enough to hold the portfolio with the owners manual and other required reading. Its back wall houses the CD changer, a bracket for a spare key fob and a recharging slot for a small flashlight. Shallow, fixed map pockets adorn the doors. The front seat cup holder is a flimsy, removable rig that sticks up out of a slot on the passenger side of the center console. The two cup holders in the rearmost section of the center console aren't convenient to either front or rear seat passengers. There's a mesh net on the transmission hump in the passenger's footwell for odds and ends. The center console cover adjusts to offer an armrest to drivers of varying heights but could use a more-resistant ratchet as it's too easily raised when all you want is to open it.