TOKYO: Shares in Japan's Takata Corp fell by a quarter on Thursday as Mitsubishi Motors became the second automaker to question the safety of its air bag inflators, casting further doubts on the future of the auto parts supplier. Mitsubishi Motors' decision to consider switching away from the component - at the heart of a global recall scandal - came a day after Takata's biggest customer, Honda Motor Co , said it would no longer use the inflators.