TRAVELING ON I-465 EASTBOUND IN INDIANAPOLIS AT APPROX. 60 MPH. THE CAR MADE A GRINDING SOUND AND THEN THE DRIVER (MY SON) LOST CONTROL AND CROSSED TWO LANES OF TRAFFIC AND HIT A RETAINING WALL ON THE LEFT-HAND SIDE OF THE ROAD. THERE WAS ONE PASSENGER WITH HIM AT THE TIME AND HE WAS FOLLOWING US HOME. WE WERE ABOUT 100 YARDS IN FRONT OF HIM AT THE TIME OF THE ACCIDENT. THE ENTIRE LEFT FRONT SUSPENSION, STEERING AND TIRE ASSEMBLY WAS HEAVILY DAMAGED. LEFT REAR TIRE AND SUSPENSION ALSO DAMAGED. SUN ROOF WOULD NOT CLOSE. VERY LITTLE EXTERIOR DAMAGE DONE SCRATCHED PAINT VERY SMALL DENTS, ALMOST ALL OF THE DAMAGE WAS DONE UNDER THE TIRE WELL.*AK