The new 'Audax' model for Rootes had its debut at Earls Court 1955 in the form of the 2-door hardtop Sunbeam Rapier. Although it had a monocoque bodyshell by Pressed Steel, convertibles were finished off by Thrupp and Maperley. The name 'Audax' was given to the project during development standing for 'Bold' and is now given to the range. Designed by Clare Hodgeman and Bob Holden Koto at Raymond Loewy Studios with clear reference to Studebaker designs they had worked on. Hillman's Minx version was launched with 1390cc engine in May 1956, and in September 1956 it was joined by the Singer Gazelle with carried Singer's own 1496 ohc engine until the Series IIA in 1958. All engines were upgraded to 1494cc during 1958. One of the biggest styling changes was given to the Series IIIA Gazelle, Minx and Rapier which gained larger front screen and rear wings in 1959. In 1961 engines were upgraded to 1592cc, but the 'Audax' cars were now demoted to sell underneath the near Super Minx. Extensive restyling was given to the Series V cars in 1963 by which time estate cars and convertibles had been culled. In 1965 the engine was uprated to 1725cc and the Audax soldiered on to be replaced by the new Hillman Hunter models in 1966.