Anciens Etablissements D’Ieteren Frères was a well established coachbuilder with a history dating back to 1805. They had produced bodywork for Bugatti, Delage, Packard, Studebaker, Rolls Royce and Hispano-Suiza.
In the 1950s they took up the rights to build the Piatti, and were also associated with Aldimi scooters.
The Piatti Archive discusses the role of D’Ieteren at some length.
In the mid-70s Roland D'Ieteren became head of the company and it expanded dramatically as main agents for NSU/Audi, becoming the largest automotive network in Belgium.
The firm remains active: dieteren.be