georg and erich heuer worked with their father in the business, later taking over from him in 1918, although the father remained active as a director till 1932. georg, notably, concentrated on car body design, producing cabriolet and other designs in the early 1930s of remarkable harmony and symmetry. his "six-light" pullman limousine design was a milestone both artistically and technically. the firm was also known for mechanically ingenious roof folding mechanisms, for which it held several patents.