2011 BMW 550I Steering Problems

THIS CAR HAVE BEEN N GREAT MAINTENANCE ALWAYS, AND SUDDENLY STARTED TO THROW WHITE SMOKE AS CRAZY... (75K MILES ONLY) I DID MY SEARCH AND TURNS OUT THAT IS A BIG PROBLEM THAT MANY BMW V8 ENGINE THAT THEY HAVE .... BIG HEADACHE TO SEE THIS KIND OF LUXURY CAR SMOKING LIKE THAT

MY 2011 BMW 550I HAS THRICE HAD THIS WEIRD RESPONSE IN THE PAST 6 MONTHS. AFTER DRIVING FOR 30M-1H SUDDENLY GOT MULTIPLE DIFFERENT WARNING LIGHTS BEFORE I LOST CONTROL OF STEERING (STIFF LIKE A DEAD BODY) AND BRAKES FOLLOWING WHICH THE CAR STALLED. IT WAS TOWED TO THE DEALERSHIP WHO SAID THIS WAS A BAD BATTERY WHICH DID NOT MAKE SENSE BUT THE CAR WAS RUNNING THEREAFTER SO I TOOK IT HOME. THE SECOND TIME THE DEALERSHIP WAS CLOSED - I WAS ABLE TO START THE CAR A FEW MINUTES LATER AND TOOK THE RISK OF DRIVING HOME. THE DEALERSHIP SAID SINCE THE CAR WAS RUNNING THEY COULD NOT RUN ANY DIAGNOSIS. THEREAFTER THE CAR RAN FINE FOR 3 WEEKS AND THEN IT HAPPENED AGAIN. THIS TIME I COULD RESTART IT BUT THE CAR WOULD ONLY MOVE A FEW FEET BEFORE STALLING. AFTER TOWING IT TO THE DEALER THEY TELL...