Just when it seemed like the head of Toyota Motor Corp. would keep a low profile until the firm's recall troubles wind down, President Akio Toyoda made a surprise public appearance and offered a solemn apology to anxious consumers.

But when the hastily arranged late evening news conference in Nagoya on Friday ended, key questions about how Toyota will address the latest safety questions about its best-selling Prius hybrid were left unaddressed, reinforcing doubts about the top management of the world's biggest automaker.

The sudden appearance of Toyoda, the 53-year-old grandson of the company's founder who took office in June, came on very short notice. Even officials of Toyota's public relations team in Tokyo were only given a few hours' notice.