Two Convertibles with some similarities, but otherwise different in most aspects such as the modifications, starting price, horsepower, fuel economy, height, and maximum occupancy. First of all, the 2016 Mercedes-Benz SL-Class SL 65 AMG is priced $32,550 lower compared to the base MSRP of the 2015 Bentley Continental GT Convertible Speed. Also, the 2015 Continental GT Convertible Speed has bigger and thirstier engine; the 2016 SL-Class SL 65 AMG gets 2 more mpg. In addition, the Continental GT Convertible Speed is slightly taller than the SL-Class SL 65 AMG. And then, you'll seat two more passengers in the Bentley Continental GT Convertible Speed than in the Mercedes-Benz SL-Class SL 65 AMG. Among similarities are the body structure, market segment, and ground shadow size.