The National Highway Traffic Safety Administration (NHTSA) is warning owners of 2010 Ford Fusion and Mercury Milan vehicles not to place any unsecured floor mats on top of standard carpeted floor mats as it could lead to unintended acceleration. The NHTSA is opening a formal investigation into the problem after three complaints that when an all weather mat was placed on top of the standard floor mats, the mat could slip forward and trap the accelerator pedal. There have been no crashes or injuries related to the problem, but the NHTSA felt an investigation was necessary. For more information, consumers can contact the National Highway Traffic Safety Administration’s Hotline at 888-327-4236 or their Ford dealer.