Robert Opron started his design work at SIMCA in 1952, moving to a furnishing design company before returning to SIMCA. Opron was interviewed by Citroen's Flaminio Bertoni but the two quickly fell out, but Bertoni still awarded him a contract. His first task was to update Bertoni's Citroen DS for 1968. His most famous work is the Citroen SM of 1970, and in the same year the small Citroen GS. Opron's final design for Citroen was the CX in 1974. After that Opron went to Renault overseeing the Alpine A310, Renault Fuego, Renault 9 and 11 and CX-sized Renault 25. Later Opron contributed to Zagato's 1989 Alfa Romeo SZ.