The Audi A8 is a big luxury sedan designed to challenge the BMW 7 Series and Mercedes-Benz S-Class. In beats them in some areas and in others it offers an individualistic alternative. It many respects, the Audi A8 has raised the bar for performance.

Three versions are available. The standard A8 features a 4.2-liter V8 and six-speed automatic transmission that deliver instant throttle response, while quattro all-wheel drive and an adaptable air suspension provide an excellent balance between handling and ride quality. The A8 offers a supreme sense of control with Gibraltar-like stability, benefits of its lightweight, highly Aluminum Space Frame that bonds the car into one cohesive unit.

The cabin is elegant and comfortable, and tops the class in finish quality. Audi's Multi-Media Interface, or MMI, integrate controls for various features and electronic systems into a big knob. It's a little easier to learn than BMW's iDrive, but it isn't easy. There is a learning curve and sometimes we find ourselves having to work harder to perform simple functions and wonder whether this is progress or burdensome technology.

The A8 L rides on a stretched wheelbase that provides more room and comfort for rear-seat passengers, not that the standard-length model is cramped.

New for 2007, both V8 models get a 20-hp boost to 350 horsepower, while improving fuel economy by one mile per gallon to an EPA-rated 18/25 mpg City/Highway.

The A8 L W12 features a 12-cylinder engine and a whopping 450 horsepower. It's the only 12-cylinder sedan from Germany's big three luxury brands with all-wheel drive.

The Audi S8, new for 2007, is powered by a 5.2-liter V10 and comes with a firmer suspension, faster steering, and bigger brakes. The S8 is distinguished by special trim and equipment inside and out. The S8 is perfect for triple digit speeds on wide-open highways and would be an excellent choice for a cross country race. It's also a good selection for getting away from enemy agents, for those in that line of work, particularly in bad weather. For driving through the neighborhood or in stop-and-go traffic, however, we found it suffers from an overly sensitive throttle that makes smooth takeoffs a bit too challenging.

Audi A8 retail at a lower price point than comparable Mercedes and BMW models.