What we have here are two Convertibles from Audi with some differences, such as the starting price, horsepower, fuel economy, height, and maximum occupancy. First of all, there is a $92,800 difference in the base MSRP. The 2015 Audi R8 Convertible has a higher starting price than the 2016 Audi A3 Convertible. Also, the 2015 R8 Convertible has bigger and thirstier engine; the 2016 A3 Convertible gets 11.4 more mpg. In addition, the roofline of the A3 Convertible is slightly higher than the R8 Convertible's. And finally, the Audi A3 Convertible seats two more passengers than the Audi R8 Convertible. Among similarities are the body structure and market segment.