OUR 2004 CHEVROLET TRAILBLAZER WITH APPROX 40,000 MILES CAUGHT FIRE WHILE DRIVING APPROXIMATELY 40 MPH. WE NOTED SMOKE BEHIND THE CAR AND BEFORE WE COULD PULL OVER OTHER DRIVERS WERE YELLING TO US THAT THE CAR WAS ON FIRE. WE IMMEDIATELY GOT TO SIDE OF ROAD, TURNED OFF ENGINE AND A LARGE FIRE WAS COMING FROM THE HOOD. A GOOD SAMARITAN RAN UP WITH A FIRE EXTINGUISHER AND PUT OUT THE FIRE THAT WAS APPROX 4 FEET HIGH FROM THE HOOD. ALL PASSENGERS SAFELY EXITED THE CAR AS SOON AS STOPPING AND DUE TO THE FIRE BEING EXTINGUISHED QUICKLY NO OTHER DAMAGE WAS DONE. THIS VEHICLE WAS RUNNING FINE WITH NO RECENT ISSUES OR SERVICE ON THE VEHICLE PRIOR TO THIS EVENT. WE HAVE NEVER HAD THE CAR SERVICED BY ANYONE OTHER THEN CHEVROLET DEALERSHIPS. WE WERE INFORMED BY THE TOW TRUCK COMPANY THAT THEY HAVE MANY 2004 CHEVY TRAILBLAZERS TOWED THAT HAVE CAUGHT FIRE. I HAVE SEEN SIMILAR EXPERIENCES DESCRIBED ONLINE BUT HAVE NOT FOUND IF THERE IS A TECHNICAL SERVICE BULLETIN RELATED TO THIS. *TR