This raid comes soon after the company revealed that a number of its SUVs were also being sold with incorrect fuel economy ratings. The Japanese government issued a stop-sale on those vehicles a few days ago. This raid also follows an internal investigation conducted by Mitsubishi to discover how this fuel economy scandal happened, and how the practices that led to it were able to continue for 25 years.
The internal investigation revealed a few contributing factors that all fell under issues with the company's culture. There was significant pressure throughout the company to reach fuel economy targets and missing them wasn't readily accepted. Questioning decisions of management was also discouraged, and it seemed the different divisions of the company weren't working well together.
The findings of this raid have yet to be revealed, but it will be interesting to see how they compare with those of the internal investigation. The Japanese Transport Ministry seems intent on preventing a repeat of this with another company considering that, according to Reuters, it "sent documents to other automakers to enforce compliance with rules for calculating mileage."