The 1954 1000 km Buenos Aires was the first major sports car race of the year and the inaugural endurance race to be held in Buenos Aires. Along with the 1000km Nürburgring, it was the only other long distance race in the series. Besides a single race in Caracas, Venezuela, it was the only annual South American race in the history of the World Sportscar Championship. A total 38 racing cars were registered for this event, of which only 36 arrived for practice and qualifying, including 550-01 and 550-02 entered by Jaroslav Juhan. The race was held over 106 laps of the 5.888 miles Autódromo Municipal-Avenida Paz, giving a distance of 624.162 miles (1,000 km). Both spyders raced without the hard top due to the seasonal hot weather conditions, where 550-01 finished 9th overall and first in class and 550-02 driven by Jose Sala Herrarte and Antonio Asturias Hall finished 13th overall and 4th in class.

In 1955, a longer section of the Autopista General Pablo Riccheri route was added, making the circuit 17.136 km in length and only 58 laps. Again two 550s were entered by Jaroslav Juhan, 550-01 and 550-12, with 550-12 taking out the podium finish and 550-01 not finishing with gearbox problems.