Two Convertibles with some similarities, but otherwise different in most aspects such as the starting price, horsepower, fuel economy, model year, and ground shadow size. First of all, the 2016 Audi S5 Convertible is priced $56,400 lower compared to the base MSRP of the 2014 BMW M6 Convertible, which is older by two model years. Also, the 2014 M6 Convertible has bigger and thirstier engine; the 2016 S5 Convertible gets 5 more mpg. And finally, the body structure of S5 Convertible is slightly smaller than that of the M6 Convertible. Among similarities are the body structure, market segment, height, and maximum occupancy.