I WAS DRIVING ON FOUR LANE HIGHWAY IN RIGHT LANE AT 40MPH. I NOTICED THE CAR STARTING TO SLOW DOWN AND WHEN I PRESSED THE GAS PEDAL IT DID NOT REACT AND THE CAR CONTINUED TO SLOW DOWN. I LOOKED AT MY GAUGES ON THE DASH AND THERE WERE NO WARNING LIGHTS AND ALL GAUGES READ NORMALLY. I THOUGHT I COULD SMELL SMOKE, AND THE CAR CONTINUED TO SLOW DOWN, AND I KNEW I NEEDED TO GET OFF THE ROAD AS TRAFFIC WAS HEAVY. AS I PULLED OFF THE ROAD INTO THE PARKING LOT FOR THE STRIP MALL, THE CAR STALLED, LIGHTS CAME ON THE DASH TO INDICATE THE CAR STALLED AND I WAS ABLE TO STOP THE CAR, PUT IT IN PARK AND TURN THE CAR OFF. I COULD SMELL SMOKE AND I COULD SEE SMOKE GOING OUT THE CAR WINDOWS FROM INSIDE THE CAR AS I HAD THE WINDOWS OPEN A COUPLE OF INCHES. THERE WAS NO SMOKE COMING FROM UNDER THE HOOD. I DEBATED WHETHER TO CALL AAA OR 911. AS THE SMOKE INCREASED I CALLED 911. I THEN WENT TO THE CAR TO GET MY PURSE. WHEN I OPENED THE PASSENGER FRONT DOOR THE CAR WAS FILLED WITH SMOKE AND I THOUGHT I COULD SEE FIRE IN THE MIDDLE ROW OF SEAT ON THE FLOOR. I OPENED THE BACK DOOR ON THE PASSENGER SIDE AND SAW FLAMES SHOOTING UP FROM THE FLOOR 6 INCHES HIGH IN THE CENTER OF THE FLOOR. I TRIED TO PUT OUT THE FIRE WITH A SNOW SCRAPER WITH THE BRUSH END, BUT I WAS NOT SUCCESSFUL. I ASKED THE DRY CLEANING LADY IF SHE HAD A FIRE EXTINGUISHER. IT TOOK 30 SECONDS TO GET THE EXTINGUISHER AND ON MY WAY BACK TO THE CAR, I COULD SEE FLAMES UNDER THE CAR AND WHEN I OPENED THE BACK PASSENGER