2004 BMW Z4 Equipment Adaptivemobility Problems

STEERING HAS A "NOTCHED" OR "STICKY" FEEL TO IT WHEN TRAVELING ON HIGHWAYS AT SPEEDS AROUND 50MPH AND HIGHER. WHEN THE NEED TO TURN ARISES AND THE STEERING WHEEL "STICKS" IN THE 'NOTCH", IT REQUIRES EXTRA EFFORT TO GET THE WHEEL OUT OF THE NOTCH, CAUSING "OVER STEER" WITH DIFFICULT RECOVERY. I WON'T LET MY WIFE DRIVE THE Z-4 AS I FEEL THIS IS A DANGEROUS CHARACTERISTIC THAT COULD RESULT IN AN ACCIDENT. MY DEALER WAS NOTIFIED OF THE SITUATION BUT WAS "UNABLE TO DUPLICATE" THE FAULT; (PRIOR TO MY WARRANTY RUNNING OUT). ON THE FOLLOWING SERVICE, WITH MY RENEWED COMPLAINT, THE DEALER WAS ABLE TO DUPLICATE AND IDENTIFY THE PROBLEM. MY BMW WARRANTY WAS EXPIRED, BUT I HAD PURCHASED AN "EXTENDED WARRANTY", HOWEVER THE "STEERING" PROBLEM WAS NOT COVERED UNDER THE NEW WARRANTY. THE COST FOR REPAIR WAS IN EXCESS OF $3000.00! I HAVE PARKED THE CAR EXCEPT FOR...