When did the first Volkswagen Beetle convertibles go into production?

Three were produced in 1948, 364 in 1949, and then went into full sales production in 1950, selling 2695 units and topping out at 19569 in 1979. All were made by the Karmann coachworks in Osnabruck Germany.

Source: Volkswagen Beetle Cabriolet, Malcom Bobbit, 2002 Veloce Publishing