DRIVING HOME ON HIGHWAY ABOUT 70MPH AND ENGINE JUST STOPPED. VEHICLE WAS IN DRIVE, BUT COASTING. GOT TO SHOULDER. PUT CAR IN PARK, ENGINE WOULD NOT TURN OVER. CALLED TOW, THEN NOTICED SMOKE COMING FROM HOOD. HUNG UP, CALLED 911 FOR POSSIBLE FIRE. AFTER HANGING UP WITH 911, SMOKE BEGAN COMING THROUGH VENTS. GOT OUT OF CAR, SAW SOME FLAMES THROUGH GRILL, CALLED 911 BACK AND TOLD WAS DEFINITELY ON FIRE AND WITH MINS ENTIRE ENGINE BAY WAS ENGULFED. CAR WAS A TOTAL LOSS.