Two Convertibles with some similarities, but otherwise different in most aspects such as the modifications, horsepower, height, starting price, fuel economy, ground shadow size, and maximum occupancy. First of all, there is a $13,850 difference in the base MSRP. The 2018 Alfa Romeo 4C Spider has a higher starting price than the 2018 BMW 2 Series Convertible M240i xDrive. Also, the 2018 2 Series Convertible M240i xDrive has a more powerful engine and gets 4 mpg less than the 2018 4C Spider. In addition, the 4C Spider body is slightly smaller than the 2 Series Convertible M240i xDrive, and in addition to that, it's also significantly shorter. And then, the BMW 2 Series Convertible M240i xDrive seats two more passengers than the Alfa Romeo 4C Spider. Among similarities are the body structure and market segment.