TL* THE CONTACT OWNS A 2011 HYUNDAI SONATA. THE CONTACT STATED THAT AFTER DRIVING THE VEHICLE FOR EXTENDED PERIODS OF TIME, OCCUPANTS WOULD BECOME FATIGUED, LIGHT HEADED, AND EXPERIENCED HEADACHES. THE CONTACT ALSO STATED THAT SHE NEARLY PASSED OUT ON ONE OCCASION. THE CONTACT TOOK THE VEHICLE TO A FIRE DEPARTMENT TO HAVE IT TESTED FOR CARBON MONOXIDE AND THE TEST CAME BACK NEGATIVE. THE FIREMAN THAT TESTED THE VEHICLE ALSO REPORTED THAT HE BECAME LIGHT HEADED AND EXPERIENCED A HEADACHE WHILE DRIVING IT. THE CONTACT SPOKE WITH THE MANUFACTURER AND WAS INFORMED THAT THERE WAS NOTHING THAT COULD BE DONE BECAUSE THE DEALER STATED THAT THERE WERE NO CARBON MONOXIDE LEAKS. THE FAILURE MILEAGE AND CURRENT MILEAGE WAS UNKNOWN. THE VIN WAS UNKNOWN.