Two Convertibles with more similarities, such as the body structure, market segment, starting price, ground shadow size, and maximum occupancy, than differences, like the modifications, horsepower, fuel economy, and height. First of all, the 2018 Mercedes-Benz SLC-Class AMG SLC 43 has a more powerful engine than the 2018 Alfa Romeo 4C Spider, and it gets 5 fewer miles on a gallon of fuel. Also, the roofline of the 2018 4C Spider is slightly lower than the 2018 SLC-Class AMG SLC 43's. Among similarities are the body structure, market segment, starting price, ground shadow size, and maximum occupancy.