Two Convertibles with more similarities, such as the body structure, market segment, ground shadow size, height, and maximum occupancy, than differences, like the starting price, horsepower, and fuel economy. First of all, the 2018 BMW M6 is priced $113,800 lower compared to the base MSRP of the 2018 Bentley Continental. And finally, the 2018 Continental has bigger and thirstier engine; the 2018 M6 gets 1 more mpg. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.