For the past decade, Audi has invested heavily in technology intended to establish itself once-and-for-all on equal terms with German heavyweights BMW and Mercedes-Benz. The company's flagship sedan, the 2005 Audi A8, suggests Audi has not only matched its primary rivals in most areas, but surpassed them in some. The A8 is Audi's largest, most sophisticated sedan: Comfortable, fast and very smooth. Yet those qualities are the baseline for full-size cars in this price range. The A8 is the newest of Germany's Big Three luxury sedans, and it raises the performance bar in many respects. It's more refined that the Mercedes S-Class, and more handsome to many than BMW's 7 Series. Nor is Audi resting on the A8's achievements. All new for model year 2004, the A8 nonetheless adds features for 2005. The line has been expanded with two new variants, including the ultra-luxurious, 12-cylinder A8 L 6.0. A8's redesign a year ago was thorough. Its wheelbase was stretched to provide even more room and comfort for rear-seat passengers, which can be crucial in this type of executive-class transport. Its 4.2-liter V8 engine was revised to generate more power, and matched to a six-speed Tiptronic automatic that allows better fuel mileage than the previous five-speed automatic. This drivetrain delivers instant response to the driver's demand for acceleration, while quattro all-wheel drive and an adaptable air suspension provide a seemingly ideal balance between handling and ride quality. Audi's unique Aluminum Space Frame, a lightweight, highly rigid structure that bonds the car into one cohesive unit, augments the supreme sense of control with Gibraltar-like stability. The A8's cabin is elegant and comfortable, and tops the class in finish quality. Audi's Multi-Media Interface, which comprises the company's attempt to integrate controls for various features and electronic systems, is easier to learn than BMW's controversial iDrive. For 2005, Audi has launched a shorter-wheelbase A8 in the United States. A standard in Europe for years, this A8 delivers all the performance and luxury for buyers who don't need such a cavernous backseat, and makes parallel parking easier. Audi also launches the elite A8 L 6.0, with its unique look, unusual W-configured 12-cylinder engine and a whopping 440 horsepower. It's the only 12-cylinder sedan from Germany's Big Three luxury brands with all-wheel drive. Finally, all A8s get two new features: Soft Touch doors, which pull the side doors shut from a partially latched position, and Automatic Key, which allows the owner to unlock the doors and start the car simply by walking up and sitting down. Better still, the new standard wheelbase A8 ($66,590) and the A8 L 4.2 ($68,500) are priced below the long-wheelbase BMW 745Li ($72,500) and standard-wheelbase 745i ($68,500), which don't offer all-wheel drive. The A8 also has a significant price edge on the rear-drive Mercedes S430 ($72,600) or S500 ($81,000) and the all-wheel-drive S430 4Matic ($75,500). The advantage holds with the 12-cylinder models as well.