Two Convertibles with some similarities, but otherwise different in most aspects such as the modifications, starting price, horsepower, ground shadow size, height, and maximum occupancy. First of all, the 2016 Audi S5 Convertible is priced $9,750 lower compared to the base MSRP of the 2015 Mercedes-Benz SLK-Class SLK 55 AMG. Also, the 2015 SLK-Class SLK 55 AMG pulls more horsepower than the 2016 S5 Convertible. In addition, not only S5 Convertible is slightly larger, but it's also taller than the SLK-Class SLK 55 AMG. And then, you'll seat two more passengers in the Audi S5 Convertible than in the Mercedes-Benz SLK-Class SLK 55 AMG. Among similarities are the body structure, market segment, and fuel economy.