I JUST ENTERED THE FREEWAY AND TRAFFIC WAS SLOW 40 TO 45 MPH. I MOVED FROM FAR RIGHT TO CENTER LANE THEN FROM CENTER TO LEFT LANE. WHEN I MOVED FROM CENTER TO LEFT I WAS TRAVELING BETWEEN 45 AND 50 MPH WHEN THE REAR OF THE CAR BEGAN TO SLIDE OUT OF CONTROL. WHEN I BUT DID NOT UNDERSTAND WHY AS THE ROADS WHERE DRY AND CLEAR. AS I TRIED TO REGAIN CONTROL THE CAR DID NOT RESPOND AND CONTINUED TO SLIDE COMPLETELY OUT OF CONTROL 180 DEGREE AND SLID SIDEWAYS INTO A WALL OF PLOWED ICE AND SNOW IN THE LEFT SHOULDER AND FLIP ON ITS ROOF. THE LOSS OF UNDERSTANDING OF HOW THIS HAPPENED HAS GIVEN ME MUCH ANGUISH AS I KNOW I HAD THE TRACTION CONTROL HANDLING ON, UNTIL I FOUND OUT ABOUT A RECALL HAVING TO DO WITH THE STEERING AND HANDLING A FEW MONTHS LATER.