The double-bubble, multi-step instrument panel in the BMW 7 Series was bashed by critics almost as frequently as the exterior styling when the car was introduced, but the interior design has worn very well. High-quality materials and elegant finish make the 2007 7 Series cabin a pleasant, luxurious and exceedingly comfortable place in which to conduct the business of driving.

The dash looks particularly clean because the iDrive system eliminates so many switches and knobs. Buttery leather is used throughout, with a loosely draped (as opposed to pulled-taut) look. Wood trim is spread tastefully on the dash, center console and armrests. We prefer the oiled-look walnut over the polished elm, and particularly over the light Elm, but you may not. In any case, a variety of materials adds interest without making the interior look busy. The standard roof liner in the 750i reminds us of fine suit material; the 760Li's roof is lined with suede-like Alcantara.

The front seats are supportive and comfortable, with adjustment in 20 directions. Some adjustments are automatic, including the headrests, which change height according to the position of the seat. Active Seat Ventilation cools the seats in the summer by blowing air through micro-perforations in the leather, and the system includes a vibrating feature.

All 7 Series sedans feature dual-zone temperature and airflow adjustment for the front passengers. The 760Li adds separate temperature adjustments for each side of the rear seat. Shutter-like slats seal off vents 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 rear roof pillars adds to the evening elegance of the rear seats. For bright days, the 760Li includes power sunshades for the rear 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. These rear seats are heated and ventilated, and adjust 14 ways, with a control that allows rear-seat passengers to move the front passenger seat forward.

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

The quiet cabin provides a perfect environment for a superb stereo, which 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, and it includes a CD changer. We'd spring for the optional Sirius Satellite Radio, which offers mostly commercial-free music, news, sports and talk. We're not so sure about BMW's HD radio option.

HD radio works, with a caveat. When it locks on a signal the clarity and fidelity is amazing, especially on the AM band. The problem is, depending on where you're driving, the radio can fluctuate from HD to standard broadcast as signal strength changes, the same way a conventional FM radio can switch from stereo to mono when the signal weakens. It can happen several times a mile, and become a bigger annoyance than it's worth.

Technology abounds inside the 7 Series. Working the multitude of systems comes closer to operating a computer than any mainstream production car before, and here's where it gets tricky. For many, it will be less than appealing. Even starting the car and putting it in gear requires different steps than years of driving have conditioned most of us to expect. Simple things like turn signals can be difficult. In the 7 Series, it took practice to learn to cancel the turn signal after a lane change, rather than making it indicate the opposite direction. Until the process becomes familiar, the 7 Series driver can drive miles with the turn signals switching from side to side.

Then there's iDrive. That's the big, round, leather-topped aluminum knob on the center console, which manages 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 recessed under the middle dash bubble. As with a menu-driven computer operating system, you may immediately reach the function you're after, or you may get another sub-menu with more selections to sort through.

The problem with iDrive is that it can be cumbersome even when you've mastered it, and insufferable until you do. It takes a fair amount of practice just to get a rudimentary grip on its operation, and you'll need to read 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 the first couple days, for example, just to figure out how to tune in a radio station that wasn't pre-set by a previous driver.

And learning isn't the only problem. Even when you know the system, you'll have to wade through various menus and sub-menus to get to the function that needs adjustment. That function may be one you could more simply adjust on a conventional dashboard by flicking a switch. More clicks are not progress, in our view, and the alleged refinements BMW has introduced over the years don't help much. The best is a return button, which sends you back to the main menu, and at least lets you start over sooner. Regardless of how cool or trendy they may be, touch-screens are much more effective.

BMW's voice-command system works reasonably well for people willing to learn how to program and use it. Basic familiarization lets you call home, check voice mail, or switch among two or three favorite radio stations. It'll do much more than that for those willing to invest some time, however. You can really impress friends (and kids) even if you set up just a few functions.

Interior storage is not one of the 7 Series' strengths, compared to more mainstream vehicles like minivans or sport-utilities, or even other high-end luxury sedans. The center console lid is split down the middle to create a pair of leather-covered access doors. The driver's side is cooled by the air conditioner, the passenger side filled with CD storage and a cellular telephone holder. The glove box is 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. The two cup holders are handsome, high-tech and practical, with sliding covers, but the sun visors don't match the quality of the rest of the interior.

And with 16.3 cubic feet of trunk space, the 7 Series ranks near the bottom of this class (the Jaguar XJ, Mercedes Benz S-Class and Lexus LS460 all have more capacity). That said, the 7 still has a large trunk, with ample room for luggage or at least a pair of large golf bags. If you really want to be self-indulgent, choose the Convenience Package or the 760Li. Both include a no-touch power trunk lid.