2006 BMW X3 SERIOUS BUCKING OF TRANSMISSION ABOVE THREE THOUSAND RPM UNDER LOAD GOING UP A HILL BUT ALSO OCCURS ON FLAT GROUND. HAD THE VEHICLE IN FOR SERVICE MULTIPLE TIMES AT TWO DIFFERENT DEALERS AND BMW DENIED THAT THERE WAS AN ISSUE. THE CAR WAS STILL UNDER EXTENDED WARRANTY. HAD SERVICE REP TAKE A RIDE WITH ME TO SHOW HIM THE ISSUE AND HE ADMITTED THAT THERE WAS AN ISSUE WITH THE CAR. IN THE END TO MAKE A LONG STORY SHORT BMW SAID THEY WOULD NOT FIX THE CAR BECAUSE IT WASN'T A LIFE THREATENING ISSUE. I WAS ON THE HIGHWAY A FEW TIMES WHEN THE CAR STARTED TO BUCK AND I HAD TO MOVE OVER INTO THE SLOW LANE BECAUSE THE CAR WOULD NOT MAINTAIN SPEED. THIS COULD LEAD TO A SERIOUS SITUATION BUT BMW DOESN'T THINK SO. *TR