The front seats are supportive and comfortable, and by that we mean all iterations in both model lines. The standard seats in the 750i adjust 14 ways. The available Comfort Seats adjust in 20 directions. Some adjustments are automatic, including the headrests, which change height according to the position of the seat. The sport package seats have bolstering on par with those in a sports car. Active Seat Ventilation cools the front and rear seats in the summer by blowing air through micro-perforations in the leather; the system includes a vibrating feature.

All 7 Series sedans feature dual-zone temperature and airflow adjustment for the front passengers, managed by familiar knobs and buttons arrayed across the center of the dash; the 760Li adds separate temperature adjustments for each side of the rear seat. Window shade-like slats seal off vent registers when and if desired. An automatic humidity control maintains relative humidity near an optimal 40 percent. Rain-sensing wipers detect misting on the windshield and automatically wipe it off.

The rear seats are roomy and comfortable. The long-wheelbase L models provide as much rear legroom as you'll find this side of a stretch limo. Waterfall LED atmosphere lighting inside the C-pillars adds to the evening elegance of the rear seats. For bright days, the 760Li includes power sunshades for the rear windscreen and rear side windows. Comfort Seats for the rear come standard on the 760Li and are available for the 750Li, along with moveable, floor-mount footrests. Rear Comfort Seats include electric heating and 14-way power adjustments, with a control that allows rear-seat passengers to move the front passenger seat forward, a great feature. Having a skilled professional drive you around while you luxuriate in back is not the worst way to travel. Rear Comfort Seats make the BMW 7 Series the ultimate riding machine.

Under power, the 7 Series cabin remains whisper quiet. The only outside sound we could hear while driving the 750i was the tires whacking over expansion joints or humming across grooved concrete. Ambient noise is wonderfully deadened inside, making conversation easy and pleasant. We could, however, detect hums, clicks and buzzes in the background generated by assorted servo motors, switches and pumps in support of all the amenities and creature comforts.

The quiet cabin provides a perfect environment for a superb stereo that delivers crisp highs, sharp bass, and clear mid-range tones. BMW's Premium Sound Package is truly sensational. Unless you have a state-of-the-art stereo at home, you'll hear things in your favorite songs you've barely noticed before. The package delivers seven channels of surround sound through 13 speakers, including a pair of subwoofers ingeniously integrated into the chassis itself; it includes a CD changer. We'd spring for the optional Sirius Satellite Radio, which offers mostly commercial-free music, news, sports and talk.

The 7 Series provides more interior storage space than some of its competitors, but storage isn't one of its strengths. The center console lid is split down the middle to create a pair of leather-covered access doors. The driver's side of our console was cooled by the air conditioner, the passenger side filled with CD storage and a cellular telephone holder. The glove box was no cave, either, being too small even to hold the owner's manual, which we had to stuff into a door map pocket or into one of the magazine pouches on the back side of the front seats. Thankfully, the CD changer has been relocated into a space in the dash above the glove box concealed by a retractable panel matching the metallic trim piece running across the dash. The two cup holders are handsome, high-tech and practical, with sliding covers. The sun visors do not appear to live up to the quality of the rest of the interior.

BMW's voice-command system works reasonably well for people willing to learn how to program and use it. You could use it to call home, check voice mail, or to switch among two or three favorite radio stations. It'll do much more than that for those willing to invest some time in it, however. A command to remember is "Options," because that will prompt the system to call out a list of recognized commands you can use. "Radio on" turns the radio on. Saying "106.7" switches the station to FM 106.7. You can also tell it to play CD track number five. You can really impress friends (and kids) even if you set up just a few functions.

Technology abounds inside the 7 Series. Working the multitude of systems comes closer to operating a computer than any mainstream production car we've seen. There's a downside to all this technology, to be sure. It requires familiarization and effort to begin to master it, and many will find the learning curve steep. Even simple, intuitive operations that we learned the first time we drove a car no longer apply in the 7 Series. You'll have to relearn old techniques just to start this sedan, release its parking brake and back it out of the driveway.

To start the car you insert the key, except that it's an electronic device rather then a traditional key (a keyless system, called Comfort Access, is optional). Then, with your foot on the brake, you press the start button. Press another button to release the electronically controlled parking brake. To shift into reverse, pull a small lever on the dash toward you and press it upwards. Snick the lever down into drive to go forward. The shifter feels more like a switch or an electronic stalk than a mechanical shifter because it is, indeed, an electronic switch. There is no mechanical link between the selector and the transmission. It's controlled by wire, and takes some practice to use as naturally as a traditional gear selector. However, once mastered, the 7 Series shifter may end up being quicker and less distracting than a traditional automatic shifter, most of which require that the driver look down to ensure the proper gear is selected, troublesome when in a hurry.

The transmission offers three shift modes, one for everyday motoring, another with quicker shifts at higher engine speeds for sporty driving and a manual shift-like Steptronic, where shifts up or down are executed by pressing buttons on the back or front of the steering wheel rim. We found the shift buttons awkwardly located, with those on the front side of the steering wheel manipulated by the thumb, which wasn't difficult, and those on the back of the wheel most readily pressed by the ring finger. In addition, the transmission doesn't hold the gear selected, automatically upshifting as the engine neared redline and readily downshifting, often two or three gears, when we floored the gas pedal.

iDrive uses on a big, round, leather-topped, aluminum knob on the center console to manage virtually everything in the cabin, including automotive functions, entertainment, communications and navigation. The iDrive knob turns like a volume knob, presses down like a switch, and slides in eight directions (left and right, forward and back, and diagonally). Corresponding menus are presented on a video screen deeply recessed in the top center of the dash. From the main or start menu, sliding the big knob toward each of the eight compass points selects a different sub-menu, or the primary menu for a system. Slide the knob due south (toward the back of the car), for example, and you'll move from the main menu to the entertainment menu. Now rotate the knob to scroll around the stereo menu, and then press down as with a mouse when the cursor lands on the appropriate function (e.g. Preset Stations). As with a menu system on a computer, you may immediately reach the function you're after, or you may get another sub-menu with more selections to spin through.

The evolution of the iDrive continues for 2006 based on what has been learned through five years of production and ownership experience. Previous improvements include two buttons just behind the main iDrive control: one that automatically returns the display screen to the main menu, and another that can be programmed with whatever sub-menu the user prefers. The first button should substantially reduce frustration levels. The second button should add convenience so that the owner can quickly get to the most often-used function (audio or climate, for example). For 2006, there are new graphics that BMW says are easier to read, more distinctive color coding of menus, easier-to-use scrollable lists in submenus, a new climate menu with clearer selections and additional on-board data.

The iDrive knob is easy for a driver to locate with the right hand without a glance; the display screen is big, and can be viewed without completely removing your eyes from the road ahead. Though improved, iDrive takes a fair amount of practice just to get a rudimentary grip on its operation, and you'll need to do some reading of the voluminous owner's manual to fully exploit it. It can be frustrating when you're at the bottom of this learning curve. It took us the first couple days of our time with a 2006 BMW 750Li, for example, to figure out how to tune in a radio station other than one already preset by a previous driver. And this despite the fitment of new hard controls on 2006 models to select band, sources and presets or tracks. Some common functions have been made easier, like pulling up a map, for instance. Unlike previous iDrive versions, where this multi-step process severely tested our tolerance for frustration, it's now quite straightforward, almost easy, involving nothing more than tapping the iDrive knob to accept the screen filled with disclaimers and caveats that appears every time you start the car and then sliding it to the right to select Navigation. That said, we expect most owners will master iDrive to the point where they use it more or less intuitively. But learning isn't the only problem. Even when you've mastered the new and improved iDrive, you'll have to wade through various menus and sub-menus to get to the function that needs adjustment. And that function may be one you could more simply operate on a conventional dashboard by flicking a switch. More clicks is not progress, in our view.

A split screen on the display can be configured to show all kinds of information depending on the mode selected by iDrive. But it's not ideal. Like many of the electronic displays increasingly popular in cars today, polarized sunglasses render some graphics in the iDrive display nearly impossible to read.

Besides iDrive, many controls do not function in the traditional fashion. We spent several miles switching back and forth between lanes on the freeway the first time we drove the new 7 Series, for example, before decoding how to cancel the turn signal without instead merely making it indicate the opposite way. Once we learned, however, it became almost second nature; and we like the three-blink lane-change feature.

Park Distance Control employs sonar sensors in the front and rear bumpers that detect objects near the car and beeps a warning with increasing frequency the closer you get. Different tones for the front and rear greatly facilitate parking in tight locations, making parallel parking quicker and more confident. While not as effective as the rear-view video system appearing on some SUVs, the system can help you avoid backing into or over something you can't see from inside the car, like a child on tricycle. We also like the park-assist system that presents a pictograph of the car and graphically displays the distance and location of the obstruction. It sounds like a gadget, but park-assist adds convenience in daily driving and can help prevent an annoying or even tragic accident. It's a good feature.