For 1958, the Porsche factory developed an advanced design of their winning RSK with a tail-finned body. At Le Mans in 1958, RSK machines finished third, fourth, and seventh in the index of performance.

Perhaps the facet that stands out most, is the Porsche's ability to score race successes against cars of greater capacity. In 1957, an american entered "Spyder" won the Le Mans 1500 c.c. class, and took first, second, and third positions in the under 2 liter class of the Swedish Grand Prix. Soon after, a Porsche works "Sebring Spyder" finished 2nd at the Targa Florio against much larger machines. In a similar car, Stirling Moss finished third against all comers at the 1958 Buenos Aires 1000 km race with a 1.5 liter RSK.