550-03 and 550-04 were sister cars with bodies fabricated in May 1953 by coach builder Weinsberg, who had aircraft production experience during the war. There were slight variations in both the bodies and finishes such as running lights directly under headlights on 550-03, but were inset towards the centre on 550-04.

The first configuration of 550-04 was as a Buckelwagen with a raised rear bulkhead which was bolted onto the existing rear deck but without the louvered gills in the sides behind the doors as found on 550-03.

Porsche had entered 550-03 and 550-04 in the November 1953 Carrera Panamericana race in Mexico as Werks cars. Both cars were shipped to New York and 550-04 was used in a photo opportunity on the docks of the Hudson river with the New York City skyline as a backdrop. The cars were sponsored by Californian Wendell Fletcher, whose company Fletcher Aviation Corporation was licensed to use Porsche engines in the planes they produced.

550-04 staying in the US with only two races including the 12 hour Sebring race in March 1954 where it finished 4th. Porsche was more prepared for the 1954 Carrera Panamericana entering both cars again, but this time with the push rod engine swapped out with 547-05, increasing the power to 117hp.

Chassis #550-04 has a documented race and ownership history that has been researched and verified through primary sources. Accurate provenance information for this car is available upon enquiry through the contact page.