Japan’s transport ministry on Thursday conducted investigations at Daihatsu Motor Co.’s headquarters in Osaka Prefecture, a day after the small car unit of Toyota Motor Corp. was forced to halt shipments at home and abroad due to a safety test falsification scandal affecting most models in its range. The ministry is looking into whether any production approval reports were rigged and will consider administrative penalties such as revoking approval if necessary. “We take seriously the fact that we betrayed our customers’ trust. We will fully cooperate with the inspection,” a Daihatsu spokesman …