There is a lot to like about the A4 cabriolet, but the car is definitely on the softer side. There is almost nothing to dislike about the S4 and S4 Avant vehicles. The S4 Cabrio is a perfect match of an understated convertible with the extreme power of a 344hp V8, a six-speed transmission and Audi's quattro permanent all-wheel drive. The S4 Cabriolet sells for about $55K.