General Motors Co (GM.N) has been sued by a Pennsylvania woman seeking to force the U.S. automaker to fix rear-end problems on more than 400,000 Chevrolet Impala vehicles for 2007 and 2008 model years. In 2008, GM told dealers to replace the rear-wheel spindle rods on Impala cars used by police because the issue could cause the tires to wear out. The lawsuit, which seeks class-action status, contends GM should also repair cars sold to consumers because many contain the same problem. It charged GM with breech of warranty and asked the court to compel the automaker the repair or replace the rear spindle rods.