DEARBORN, Mich. (March 28)—William Clay Ford Jr., Ford Motor Co. chairman, is being questioned this week by plaintiffs' attorneys suing his company and Bridgestone/Firestone in lawsuits stemming from hundreds of rollover accidents involving Ford Explorers equipped with Firestone tires. "During the past year, Ford Motor Co. has voluntarily produced dozens of witnesses who had substantial firsthand knowledge of the matter from all different levels and areas," the company said in a prepared statement. Meanwhile, Ford has replaced nearly 11 million of the 13 million Firestone tires it recalled in May, according to a Ford spokesman. The recall officially ends March 31, but it is already finished as far as Ford is concerned, he said. "We don't think there can be many more tires out there. For months we've had plenty of tires in stock, we've advertised the replacement program everywhere, but dealers report very light traffic in replacement customers."