I HAD BEEN USING THE ADAPTIVE CRUISE CONTROL AT HIGHWAY SPEED ON THE WESTBOUND CA 134 IN GLENDALE/BURBANK, CA. I HAD TO MERGE INTO TRAFFIC FROM THE HOV LANE DISENGAGING THE CRUISE CONTROL. I THEN USED THE AUTO TRANSMISSION TO SHIFT TO A LOWER GEAR TO GAIN MORE TORQUE IN CHANGING LANES WHEN THE CAR WENT INTO A STALL AND LOST ALL POWER. CONSEQUENTLY WE WERE REAR-ENDED BY ANOTHER CAR. OUR CAR WENT INTO A LOCKOUT AND HAD TO BE PUSHED TO THE SHOULDER BY THE CALIFORNIA HIGHWAY PATROL. I DON'T KNOW IF THIS WAS A RANDOM EVENT OR A GLITCH IN THE ON-BOARD COMPUTER.OR SOMETHING ELSE TOTALLY UNRELATED. *TR