An Audi R8 V10 accelerates through a tunnel producing its iconic naturally aspirated sound. The echo amplifies the aggressive high-revving V10 engine.

The Audi R8 made a remarkable impact on the market during its 17-year production run, but it was especially loved in the US.

How much is a single horsepower worth? About $295, according to Audi. The math works like this: Audi charges $191,150 for the 610-hp R8 V10 Plus and $164,150 for the regular 540-hp R8 V10, a $27,000 ...