Two Convertibles with some similarities, but otherwise different in most aspects such as the model year, starting price, horsepower, fuel economy, ground shadow size, and height. First of all, there is a $64,800 difference in the base MSRP. The 2021 Mercedes-Benz AMG GT Roadster, a newer vehicle by three model years, has a higher starting price than the 2018 Alfa Romeo 4C Spider. Also, the 2021 AMG GT Roadster has a more powerful engine and gets 11 mpg less than the 2018 4C Spider. And finally, not only 4C Spider is significantly smaller, but it's also slightly shorter than the AMG GT Roadster. Among similarities are the body structure, market segment, and maximum occupancy.