Two Sedans with some similarities, but otherwise different in most aspects such as the modifications, horsepower, fuel economy, ground shadow size, model year, and height. First of all, there is a difference in model years. The is 2 years newer. Also, the 2018 Flying Spur W12 S has bigger and thirstier engine; the 2020 A4 gets 14.5 more mpg. In addition, the A4 is both significantly smaller and slightly shorter than the Flying Spur W12 S. Among similarities are the body structure, market segment, and maximum occupancy.