2008 CADILLAC STS Unknown Or Other Problems

SUDDENLY LOST NAVIGATION SYSTEM, WHICH ALSO SHUT DOWN CLOCK AND OTHER APPLICATIONS WITHIN THAT SYSTEM. HAD IT CHECKED OUT AT TWO DIFFERENT DEALERS, THEY WERE UNABLE TO FIND THE PROBLEM. CALLED GM CUSTOMER CENTER AND WAS TOLD THIS IS A LONG STANDING PROBLEM, SOMETHING TO DO WITH THE UNIT BEING UNABLE TO SYNCHRONIZE WITH NEW SATELLITES FOR GPS. WROTE TO GM HQS, OT A REPLY BACK THAT "IT WAS BEING WORKED", WITH NO EXPECTED DATE FOR A FIX. AFTER DOING ADDITIONAL RESEARCH, FOUND THIS ISSUE HAS INDEED BEEN HAPPENING TO THIS AND SIMILAR CADILLAC SERIES VEHICLES; AND THAT GM HAS NO PLAN FOR A FIX. I BELIEVE THIS IS A SAFETY ISSUE AS IT OCCURS RANDOMLY AND IN IN THE WRONG LOCATION AND WRONG SITUATION COULD SUFFICIENTLY DISTRACT DRIVER TO CAUSE AN ACCIDENT. AT THE LEAST GM SHOULD BE NOTIFYING OWNERS OF THE PROBLEM AND POTENTIAL HAZARD.

AIR BAG ALERT SAYS SERVICE AIR BAGS THIS SHOULD BE COVERED AS MANY OF THESE BAGS HAVE BEEN RECALLED. SECOND PROBLEM: WHEN TURNING OFF THE IGNITION, IT KEEPS DINGING AND SAYS PUT CAR IN PARK EVEN THOUGH IT IS IN PARK. THIS DINGING NOISE LASTS MAYBE 10 SECONDS TO A MINUTE. SOMETIMES SHIFTING OR PUTTING FOOT ON BRAKE AGAIN STOPS THE DINGING.

CHECK ENGINE LIGHT ON VEHICLE START SHUTTING DOWN WHILE VEHICLE WAS IN MOTION ON A PA INTERSTATE AND ON A CITY STREET THIS HAS HAPPENED ON SERVAL OCCASION , THEN THE PARK TO SHIFT LIGHTS COMES ON AND THE VEHICLE AT THAT TIME IS UNABLE TO SHUT OFF. AT LEASE THREE TIME THIS YEAR 2016 (APR#7TH OCT 26TH AND NOV 3RD EACH TIME THE VEHICLE HAD TO BE TOWED, APPROX SIX TIME SINCE I PURCHASED THE VEHICLE IN NOV 2011.

AIR BAG SENSORS GOING BAD OR CORRODED. SHOULDN'T THEY LAST THE LIFE OF THE VEHICLE?