Ford and Mazda are warning the owners of more than 475,000 older vehicles in the U.S. not to drive them because they have dangerous Takata air bag inflators that have not been replaced. The warning issued Tuesday covers more than 374,000 Ford, Lincoln and Mercury vehicles from the 2004 through 2014 model years and nearly 83,000 Mazdas from the 2003 through 2015 model years. The National Highway Traffic Safety Administration says the inflators can explode with too much force in a crash, blowing apart a metal canister and shooting fragments that can severely injure or kill people.