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 and horsepower. First of all, there is a notable difference in the starting price of the 2017 FIAT 124 Spider, which is $6,560 less than the base MSRP of the 2017 Mazda MX-5 Miata RF. And finally, the 2017 124 Spider has a more powerful engine than the 2017 MX-5 Miata RF. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.