DRIVING ONTO ON RAMP OF HIGHWAY FROM PRIOR HIGHWAY AT APPROXIMATE SPEED OF 30 MPH. DRIVER NOTICED A LURCH FROM FRONT OF VEHICLE. UNKNOWN PART THAT WAS INVOLVED. POSSIBLY TRANSMISSION OR FUEL LINE BUT ONLY SUSPICION WITH NO EVIDENCE LEFT TO INVESTIGATE (SEE PICTURES INCLUDED). ACCELERATION NO LONGER ENGAGING. DRIVER PULLED VEHICLE OVER TO SIDE OF HIGHWAY. DRIVER AND PASSENGER EXITED THE VEHICLE. AFTER A FEW MINUTES, NOTICED A STREAM OF SMOKE EMITTING FROM UNDER HOOD OF VEHICLE. SMALL FIRE NOTICED AT BOTTOM OF CAR. WITHIN MINUTES THE CAR WENT UP IN FLAMES. EMS EXTINGUISHED FIRE EVENTUALLY. TOTAL TIME OF INCIDENT 10-15 MINUTES.