WHILE ROUNDING A GRADUAL CURVE AT APPROXIMATELY 50MPH SUDDENLY LOST STEERING CONTROL AND WENT OFF ROAD. EXAMINATION OF VEHICLE SUBSEQUENT TO THE ACCIDENT REVEALED LOSS OF CONTROL CAUSED BY SEVERELY RUSTED RIGHT (PASSENGER SIDE) FRONT SUBFRAME AND APPROXIMATELY 8 INCH HOLE AND BENDING/CRACKING OF SUCH DUE TO THE RUST, THIS ON A VEHICLE WHICH IS OTHERWISE PRISTINE (THERE IS ABSOLUTELY NO RUST ELSEWHERE ON THE VEHICLE). I URGE NHTSA TO REQUIRE HYUNDAI TO ADDRESS WHAT I HAVE NOW LEARNED IS A VERY COMMON PROBLEM WITH THE MODEL IN QUESTION, ESPECIALLY BEFORE ANY OTHER LIVES ARE PUT IN JEOPARDY OR LOST DUE TO WHAT IS CLEARLY AND OBVIOUSLY A GROSS MANUFACTURING AND/OR DESIGN DEFECT. NOTE THAT I CONSIDER THE SITUATION TO CONSTITUTE NO LESS THAN AN EMERGENCY AND THAT UNTIL CERTAIN MODEL YEARS OF THE HYUNDAI SONATA ARE UPDATED WITH A REVISED/NEW SUBFRAME THEY SHOULD NOT BE DRIVEN AND INDEED ARE NOT SAFE TO BE DRIVEN. AT PRESENT MY VEHICLE IS NO LONGER ROAD WORTHY DUE TO THE RUSTED SUBFRAME AND AS IT IS 4 MONTHS OUT OF WARRANTY (WARRANTY PERTAINING TO RUST THROUGH) I FORESEE THAT I WILL HAVE TO BEAR THE EXPENSE OF THE REPAIR (SUBFRAME REPLACEMENT) MYSELF. *TR