i was driving on the freeway. The GPS system and my whole dash board's light has just shut off suddenly .. and right after i park on the side and turn off the car. It won't start back on after .... and the day before this happen , the GPS system was shut down while i m driving .. and then it automaticlly turn back on and shows that my cruise control has problem ... any item why ..? i m towing my car back to san francisco from lake tahoe now ... really need some experts answer my questions .... 2004 BMW 530i with 53k on it ....