DRIVING HOME FROM WORK ON A MODERATELY HOT DAY (91 DEG AT START OF DRIVE, 80 DEG AT TIME OF INCIDENT ABOUT 55 MINUTES AFTER START), SOME STOP-N-GO TRAFFIC FIRST 40 MINUTES, THEN A STEADY NORMAL CLIMB INTO FOOTHILLS (FROM ABOUT 5400' TO 8200') ON PAVED ROADS, AS VEHICLE WAS TURNING RIGHT AT A Y-INTERSECTION AT TOP OF A HILL, A LARGE BANG WAS HEARD IN THE ENGINE COMPARTMENT FOLLOWED BY EXCESSIVE AMOUNTS OF GREY SMOKE EMANATING FROM SAME. ENGINE TEMPERATURE WAS NORMAL AT THE TIME (FAN HAD ENGAGED A FEW TIMES ALONG THE WAY TO KEEP WITHIN RANGE) AND NO WARNING LIGHTS WERE PRESENT BEFORE OR AFTER INCIDENT. IMMEDIATELY PULLED OVER AND OPENED HOOD. WITHIN ABOUT A MINUTE OF STOPPING A SMALL FIRE BROKE OUT ABOVE THE DRIVERS SIDE MANIFOLD/CAT. I WAS ABLE TO EXTINGUISH USING A TOWEL, BUT NOT BEFORE THE FIRE HAD MELTED SOME WIRE BUNDLES. INITIAL INSPECTION INDICATED A POWER STEERING (ATF) FLUID RUPTURE THAT SPRAYED THE ENGINE COMPARTMENT, SUBSEQUENTLY FLASHING FROM THE HEAT OF THE CATALYTIC CONVERTER. FORTUNATELY, SITUATION WAS HANDLED QUICKLY BEFORE THE CAR BECAME ENGULFED (AS I'VE NOW LEARNED HAS HAPPENED SEVERAL TIMES WITH THIS VEHICLE MODEL). VEHICLE IS BEING TOWED TO JEEP DEALER TOMORROW FOR REPAIR. I HAVE NOT YET HAD THE OPPORTUNITY TO SPEAK WITH JEEP REGARDING THIS INCIDENT, BUT FEEL A FAULTY DESIGN HAS PUT MY SAFETY AT RISK. I WILL HOPEFULLY BE ABLE TO PROVIDE MORE INFORMATION TO THIS SUBMISSION ONCE AVAILABLE...