AFTER HAVING DRIVEN MY PRIUS NEARLY 15,000 MILES IN ALL TYPES OF WEATHER (EXCEPT SNOW) AND ON RESIDENTIAL ROADS AS WELL AS INTERSTATE HIGHWAYS WITH NO STEERING PROBLEMS, ON A SINGLE DAY ON RESIDENTIAL STREETS AT 20 TO 25 MPH AND GENTLE RAIN, IT HYDROPLANED TWICE WITH DAMAGES EACH TIME TO THE CAR AND TO A FIRE HYDRANT ONCE. EACH EVENT WAS WHILE GOING AROUND A GENTLE LEFT CURVE AT REASONABLE SPEED. THE FIRST TIME, I WAS ABLE TO CORRECT AND SPIN OUT 360 DEGREES WITH THE LEFT QUARTER-PANEL HITTING A ROADSIDE GARBAGE CONTAINER. THE SECOND TIME, THE CAR DID NOT RESPOND TO ANY STEERING MANEUVERS NOR THE BRAKES WHEN APPLIED. THE CAR STOPPED ONLY AFTER COLLIDING WITH THE FIRE HYDRANT. SIGNIFICANT DAMAGE WAS SUSTAINED IN EACH COLLISION. I HAVE TRAVELED THIS STREET SEVERAL TIMES DAILY, OFTEN ON RAINY DAYS, AND NEVER BEFORE HAD ANY STEERING PROBLEMS. IT WAS AS THOUGH SOMETHING HAD CHANGED IN THE STEERING CONTROL ON THIS DAY. I WAS SOBER AND UNIMPAIRED. *TR