Henry Chapron saw an opportunity to built an open-top version of the Citroen ID19/DS after the car was launch on the market, a car that was in high demand, but Citroen didn’t want to build it.
Chapron started to build the open-top version of the ID19 in 1958, asking Citroen to provide him the platforms. When the carmaker said no, he bought complete vehicles and transformed them. He built 25 units in just one year. Citroen allowed Chapron to become a subcontractor and sold its open-top cars in the carmaker showrooms, forced to see the car’s popularity. Moreover, that version was showcased in Citroen’s booth at the 1960 Paris Motor Show. The Goliath was beaten again by David (who, in this case, was named Henry).

By 1968 the carmaker worked closely with the independent contractor, but it imposed several rules and design cues to follow, and those were acceptable. The DS21 featured the same front fascia as the four-door sedan version, with glass-covered dual headlamps. Its doors were longer than a regular DS, and the A-pillars were elegantly shaped to look like they were manufactured on the Citroen’s assembly line.

Inside, the DS21 featured exclusive leather upholstery but kept the same dashboard as the sedan version. In the back, the coachbuilder had to push the bench forward and store the canvas-top behind. That resulted in a small knee room left for the rear passengers. Chapron built only 483 DS21s out of the total of 1365 convertibles. The others were based on the ID19 and DS19.

Under the hood, the DS21 Cabrio (Decapotable) featured the same 2.2-liter gasoline engine from the regular DS21, paired with a four-speed manual or a 4-speed semiautomatic gearbox.