General Motors Co.’s record recalls of nearly 30 million cars and trucks across the globe, including those for ignition-switch defects, has so tainted the brand that every one of its customers has lost money, according to plaintiffs attorneys planning a nationwide class action against GM next month.

That claim will be the heart of a consolidated complaint lead attorneys in the ignition-switch litigation plan to file by Oct. 14. GM, which has sought to limit its legal liability to claims arising from the ignition switch, moved in U.S. bankruptcy court on Aug. 1 to ban consumer class actions filed over the subsequent recalls.