Japan's investigation into dangerous air bags is leading to a remote scrapyard in the central Gifu prefecture, where the explosion of a car model not included in current recalls suggests automakers may have to yet again expand their safety campaigns. In the latest incident, an air bag from Takata Corp., the Tokyo-based company at the center of the crisis, deployed with such force that it shattered the windshield and sprayed metal shards on the floor of the Toyota Motor Corp. subcompact, said Akihiro Wakayama, a manager at the Chikamatsu Shokai Co.