Audi's flagship provides smooth and effortless acceleration yet attains commendable fuel economy even with all-wheel drive. The car handles crisply and holds the road tenaciously, making it one of the sportiest luxury sedans we've tested. The ride is firm and steady, but not as cushy as in the Mercedes-Benz S-Class. Interior ambience, quality of materials, and craftsmanship are top-notch. The front seats are exceptionally comfortable and supportive, with a variety of massage settings. Demerits include controls that are daunting at first, and a relatively small trunk. Engines range from diesel and gas V6s to a V8, turbo V8, and a W12.