2005 BMW 6 Series Steering Problems

SOME DAY WHEN I COME OUT TO MY CAR IT WANT GO IN DRIVE AND DYNAMIC MALFUNCTION & TRANSMISSION MALFUNCTION POP UP ON THE SCREEN

I WAS DRIVING ON THE HIGHWAY AND MY BMW 645 FAULT MESSAGE DISPLAYED (TRANSMISSION RELATED MALFUNCTION,DRIVE MODERATELY). AFTER THAT,THE SERVICE ENGINE SOON LIGHT CAME ON,ALONG WITH A NEW FAULT MESSAGE THAT DISPLAYED (INCREASED EMISSION). AFTER THAT, THE CAR SPEED ABRUPTLY WENT FROM 60, TO (WHAT FELT LIKE FIRST GEAR),THEN JUST CUT OFF!! THERE WERE CARS AND TRUCKS ALL AROUND ME,DOING THE SPEED LIMIT OF 60 OR HIGHER,JUST MISSING ME,WHILE I'M SITTING STUCK IN THE MIDDLE OF THE HIGHWAY!! I PROCEEDED TO RESTART THE CAR,AND IT STARTED, WITH NO FAULT MESSAGES;NO SERVICE ENGINE LIGHT; AND DROVE FINE FOR A FEW DAYS,AND THEN DID THE SAME THING AGAIN!! I TOOK THE CAR TO A BMW REPAIR SHOPPED TO HAVE THE FAULT CODES READ, WHICH END UP BEING A LONG LIST OF CODES, THAT THE MECHANICS COULD NOT FIND THE REAL CAUSE OF THE ISSUE. SO,I HAD THE SHOP REPLACE MY SPARK PLUGS; IGNITION COIL; AND RESET THE COMPUTER CODES. THE CAR DROVE OKAY FOR ABOUT A MONTH,AND THEN DID THE SAME THING AGAIN!! I DON'T KNOW WHAT TO DO,THIS PROBLEM COULD CAUSE ME TO END UP IN A SERIOUS ACCIDENT,I AM AFRAID TO DRIVE THE CAR!! AS OF 07/06/2014, MY BMW 645 IS OFTEN SHOWING FALSE; LOW OIL MESSAGE; INCREASE EMISSION; TRANSMISSION MALFUNCTION; AND CLEAR AFTER TURNING CAR OFF, AND RESTARTING THE CAR!! I AM SO CONFUSED ABOUT THIS BMW 645!! *JS

TL* THE CONTACT OWNS A 2005 BMW 645CI. THE CONTACT STATED WHILE DRIVING 20 MPH THE STEERING FAILED AND SHE LOST CONTROL OF THE VEHICLE MOMENTARILY. AFTER REGAINING CONTROL OF THE VEHICLE, SHE DROVE IT HOME. THE VEHICLE WAS TAKEN TO AN AUTHORIZED DEALER WHERE THEY WERE IN THE PROCESS OF DIAGNOSING THE FAILURE. THE FAILURE MILEAGE WAS 57,000.