Two Convertibles with some similarities, but otherwise different in most aspects such as the starting price, ground shadow size, maximum occupancy, horsepower, fuel economy, and height. First of all, there is a $17,300 difference in the base MSRP. The 2018 Alfa Romeo 4C Spider has a higher starting price than the 2017 Audi A5 Convertible. Also, the 2018 4C Spider has a more powerful engine than the 2017 A5 Convertible, but it gets 4 more miles on a gallon of fuel. In addition, the 4C Spider body is significantly smaller than the A5 Convertible, and in addition to that, it's also slightly shorter. And finally, the Audi A5 Convertible seats three more passengers than the Alfa Romeo 4C Spider. Among similarities are the body structure and market segment.