Mitsubishi Galant GTO 1st generation (A53C/A55C/A57C)

In the United States, pony cars, affordable small coupés aimed at young people and women, were in fashion. Back from his studies, Kamisago argued that this wave would eventually reach Japan, and put forward a fastback proposal as a derivative of the Colt Galant. A two-door hardtop was already in development within the company, and his proposal was not accepted. Kamisago still did not stop working on it: he scrapped his own smooth, European-style early design and redrew it in search of a hotter impression. This produced a ducktail form that mass-production sports coupés had never had. In May of the following year, during an inspection by executives, it caught the eye of Managing Director Makita, and it was decided to build a show car and gauge the reaction at the Tokyo Motor Show. Lined up under the name GTX-1, the car caused a great stir.

The design department could borrow the wind tunnel at the nearby Nagoya Aircraft Works between aircraft tests. As they repeated tests of building up and cutting away clay on a 1/5 model, they found that cutting the rear end off sharply gave less drag and lift than rounding it, and the ducktail shape was settled. But the engineers in body design and production engineering balked, saying the trunk lid, with its combination of concave and convex surfaces, and the pointed trailing edge of the rear quarter panel could not be made with presses. To the idea of rounding off the corners, Kamisago strongly objected that this was the key to the design. The engineers made it real with a laborious method: pressing the panel in two pieces, welding them, building up solder and finishing with a grinder.