2010 Audi S5 Cabriolet

The four-seat premium convertible segment has become stagnant, but that's about to change. BMW fired a new 3-series convertible at its competition for the 2008 model year, and two years later, shots are finally ringing back. The 2010 Audi S5 cabriolet - along with its less sporty A5 brother - will be among the first to join the fight, closely followed by the Infiniti G37, Lexus IS, and Mercedes-Benz E-class droptops.

The sexy S5 cabriolet replaces the S4 cabrio, and since it's based on the gorgeous S5 coupe, it's longer, lower, and wider than the old car. Although the Infiniti and the Lexus join BMW in using folding hard tops, Audi remains faithful to fabric for several reasons. (Mercedes-Benz will, too, for its upcoming E-class convertible, which replaces the CLK.) Styling is the most obvious - cloth tops don't suffer from the bubbly proportions that usually afflict folding hard tops. Using fabric also allows Audi's designers to play with two-tone color combinations and different textures to give the vehicle more visual interest. Of course, there are practical concerns, too: a fabric top usually weighs less and takes up less trunk space when folded. It also helps to endow the S5 with a large cargo pass-through behind its split-folding rear seats and can be lowered in only fifteen seconds - while moving.

Other than the risk of a thief slicing open the roof, drawbacks are few. In fact, Audi boasts that its so-called acoustic roof, standard on the S5, provides interior sound levels comparable to those in a closed car, and it even features overhead LED map lights for the rear seats - which, by the way, offer reasonable legroom and, despite bolt-upright backrests, are comfortable enough for a pair of six-footers on short journeys.

The A5 Quattro droptop, set to launch two months after the S5, will use a conventional six-speed automatic transmission with a choice of either a torquey 2.0-liter turbo four or a sonorous 3.2-liter V-6. A front-wheel-drive version will also be available with the 2.0T and a continuously variable transmission.

The S5 uses Audi's new 3.0-liter supercharged V-6, which will be phased in as a replacement for the normally aspirated 4.2-liter V-8 that's in the S5 coupe. Producing 333 hp and 325 lb-ft of torque - but no supercharger whine - it pulls the S5 to 60 mph in about five and a half seconds. The menacing V-8 sound track is replaced with a Hoover whoosh - the price we pay for downsizing - but the forced-induction V-6 provides significantly better fuel economy with comparable output.