At first glance, the Audi A8 has crisp, uncluttered lines with aggressively swept back headlights and roofline. Filling the wheelwells is a choice of wheel designs and sizes ranging from sedate to sporty. All in all, this is an understated, handsome sedan that doesn't shout, "I've got money," yet still exudes class.

Inside the Audi A8, a spacious and beautifully finished interior greets the driver and passengers. Audi has a strong reputation for having what many consider the best cabins in the business, and the A8 maintains that lofty standard. Regardless of cost, there's nary a car that could top the top-shelf materials and design flair of the A8's inner sanctum. Audi's Multi-Media Interface (MMI) handles everything from the navigation and audio systems to the adjustment of the driver-selectable air suspension. MMI features a 7-inch monitor that automatically glides (and hides) into the dash when not in use. Mounted in the console and operated via a simple twist-and-press knob and four large buttons that surround the knob, Audi's MMI may draw comparisons to BMW's iDrive system. But unlike iDrive, MMI is simple and intuitive to operate.

Under the hood if this Audi car you'll find one of two engines. For starters, there's a refined 4.2-liter, 40-valve V8 that makes a scintillating 335 horsepower and 317 pound-feet of torque. If that's not enough, consider the 6.0-liter W12 power plant, which provides 450 hp, 428 lb-ft of torque and a 5.8-second 0-to-60-mph time. In either case, a six-speed Tiptronic automatic transmission sends the power to all four wheels through Audi's quattro all-wheel-drive system. Under the A8's aluminum skin, Audi employs an aluminum alloy space frame that is stronger and lighter than a comparable steel structure. This architecture has 20-percent fewer parts than the previous-generation Audi A8, yet boasts considerably greater (60 percent) torsional rigidity.

Audi's engineers are especially proud of the A8's air suspension, claiming it provides the handling of a sports car with the ride of a luxury sedan, and based on our experience, they're not too far off. The adaptive air suspension adjusts itself to road and driving conditions, automatically firming up when the car is pressed through the curves and softening when cruising down the interstate. The driver can select one of four settings for the adaptive system: dynamic (lowest ride height and firm damping), automatic, comfort and lift (raises the car up for travel on rough roads). With its polished demeanor, spacious and luxurious cabin and capable road manners, the 2006 Audi A8 leaves little to be desired. And at a price tag thousands less than its chief rivals, we would strongly suggest visiting the dealer of the four rings before putting down your big money.

Three versions of the Audi A8 are offered: a standard-wheelbase V8 sedan, the long-wheelbase V8 L sedan for those who need maximum rear legroom, and a W12 version of the L. The question with this Audi car isn't what's standard, it's what isn't. A DVD-based navigation system, 16-way power front seats and HID headlights are on the roster, as is a 12-speaker Bose audio system (with a glovebox-mounted CD changer) designed exclusively for the A8. The elite W12 adds keyless startup, power door closers, four-zone climate control, ventilated/massaging front seats, seat heaters and four-way lumbar for all passengers, an Alcantara headliner and a wood steering wheel; these features are optional on other A8s. Other options include adaptive cruise control, a personal refrigerator and a sport package for V8 models that includes a sport-tuned suspension, 19-inch wheels and steering wheel shift paddles. An available Audi Exclusive package, available in Red and Anis Yellow, includes Valcona leather seats with contrasting piping (and floor mats to match) and unique wood trim.

Standard A8 and A8 L models come with a 4.2-liter, 40-valve V8 that generates 335 horsepower and 317 pound-feet of torque. Named after the engine that makes it special, the W12 model has a 6.0 liter, 12-cylinder engine that make 450 hp and 428 lb-ft of torque. The engine consists of two narrow-angle, 15-degree V6 engines joined at the crankshaft, a more compact design than a conventional V12. Both engines are matched to a six-speed Tiptronic automatic transmission that drives all four wheels through Audi's quattro all-wheel-drive system.

Peace-of-mind features include stability control, 10 airbags (including four side, front knee and full-length head curtain) and a first aid kit in the rear center armrest.

Throttle response is gratifying with either engine. Whether taking off from a stoplight or jetting up to cruising speed on the freeway, a solid rush of power is always on tap. The main difference is that the W12 simply has more power on reserve. Powerfully reassuring brakes that are easily modulated have no problem reining in the Audi A8. The air suspension is well sorted; left in automatic mode the system works just fine providing a soft but not mushy ride and solid composure through the twisty bits. And when used in the dynamic setting, body lean is kept to an absolute minimum, making the A8 feel more like a compact sedan rather than a large flagship sedan.

Whether you sit in the pilot's seat or stretch out (and with 42 inches of rear legroom in the L, we mean stretch out) in back, everything you see and touch in the 2006 Audi A8 bespeaks the highest quality. Generous fillets of dark or light wood, suede trim and aluminum accents are arranged attractively. With 16-way power adjustment (including upper seatback angle for the shoulders) and a power tilt/telescoping steering wheel, finding a comfortable driving position is easy for short and tall folk alike.