The old workshop in via della Chiusa was by this time a distant memory. The number of vehicles ordered was so high that for several years now the business had been shifted to via Montevideo, number 19.
The factory took up an entire block, covering an area of 32,000 m2 of which 20,000 were floor area. With its 400 employees it was the biggest coachbuilding firm in Italy.
More than 100 cars took shape here each year, components were produced for the budding automobile and aeronautics industries and work was also carried out on behalf of third parties. In addition to chroming vehicle parts, the galvanic chroming division, the first of its kind in Italy, did work for outside companies on components, metal sundries and fittings. It was here, too, that all the finishings that went to make up the interiors of the carriages of the Wagons-Lits railway company, and even of the legendary Orient Express, were produced.
Well-dressed people could often be seen wandering through the various departments in the afternoons. These were customers who, accompanied by managers, would be checking the lines of their new vehicles chosen months beforehand from pictures and examining materials and colour samples for the definitive choice of finishings.
It would appear that some of these people regularly had aperitifs on the Castagna premises with friends with whom they shared the joys and sufferings of their choices.

Struck by the level of creativity that the system had reached, a well-known journalist of the period coined the term “dream factory” to describe the premises.