Charles Deutsch and Rene Bonnet were friends from 1932, Deutsch was a Civil Servant and landlord to Bonnet, and together they built some racing specials for their own use in the 1930s. After WWII D-B was formed, and cars were produced with the help of Panhard et Levassor who let their engines be used in return for testing and development. The HBR4 and 5 was the most successful product of the D-B joint venture and was launched as the DB Coach at the 1954 Salon de Paris. Bodies were built in fibreglass by Chausson, but after 100 the tooling was transferred to another company and the HBR5 was only the second series production of a fibreglass car. The early HBR4 had the 745cc Panhard Dyna X engine, whilst the HBR5 had the later 848cc and 954cc Panhard PL17 engines. Around 430 HBR5 D-B were built along with some specials and competition versions. When Deutsch and Bonnet dissolved their venture in 1961, Panhard asked Deutsch to develop a car for the 1962 Le Mans race, and this was an evolution of the HBR5.