A major market share for subway train air-conditioners was not enough.
Next was the world's largest subway system, New York City Transit.

World Class: Mitsubishi Electric subway-car air-conditioning systems

Air-conditioning has become an essential part of life. From homes and offices to trains and cars, it's hard to find a space that is not air-conditioned today. The theme of this article is subway-car air-conditioning, a surprisingly complex field requiring wide-ranging expertise. First, the specifications are varied according to region, type of railway, and rail car. The manufacturing process is difficult and requires much hand-made production by skilled engineers. For these reasons, it requires made-to-order parts from many different fields. Mitsubishi Electric is proud to state that it has shipped almost 110,000 units in this field since 1950, securing 65% of the Japan market and over 10% of the world market, making it without doubt, a major supplier. A significant factor in the development of its international business was the constant supply of units since 1991 to the New York City Transit (NYCT) subway system.