Automakers have “ultimate responsibility” for the costs of replacing potentially deadly Takata Corp airbags, no matter what happens to the Japanese supplier, the top US vehicle safety regulator said on Wednesday. Mark Rosekind, the head of the National Highway Traffic Safety Administration, told reporters in Detroit he is concerned that not enough is being done to find and fix more than 300,000 older vehicles, mostly made by Honda Motor Co, that have Takata airbags with a 50 percent chance of exploding in a crash. Honda said it continues to explore and evaluate new methods of convincing owners of vehicles affected by Takata airbag inflator recalls to complete the necessary repairs. Honda associates have started conducting targeted home visits to owners of the older-model 2001-2003 vehicles that the NHTSA has determined are at the highest risk of experiencing a Takata inflator rupture, Honda said in a statement. Takata is seeking a buyer, amid speculation the company could seek bankruptcy protection as part of a deal. Rosekind said his agency believes it has “several layers of protection” to assure that recalls of up to 70 million potentially defective Takata airbag inflators are completed as agreed with the company. Automakers worldwide are ramping up the industry’s biggest-ever recall after Takata, under pressure from US authorities, agreed earlier this year to declare more of its air bags as defective in the United States and other countries. US safety regulators have linked 11 deaths in the United States to Takata airbags that ruptured, sending metal shrapnel flying inside vehicles. The most-recent reported US fatality was of a 50-year-old woman who died in a 2001 Honda Civic after a Sept. 30 crash in Riverside County, Calif.