2008 Ford Mustang electrical system problems

2008 mustang gt 4.6l, shaker 500 radio defect, fuel sensor defect- vehicle is a daily driver, parked it for 4 days over holiday, battery dead. Determination from ford dealer service was shaker 500 6 disc changer was cycling discs with the engine and ignition turned off. Dead battery then prevents passenger from entering the vehicle due to lowering of glass when door latch releases.

Vehicle was being driven in a parade when it suddenly accelerated or surged at children walking in front two separate times. The first time the vehicle was stopped by the brake and the second time with the brake and the gear shift to neutral. Car was taken to ford dealer, the could not duplicate problem, but reprogrammed the computer and decarbonized the engine with no guarantee that the problem was fixed. Complaint file was started by ford 10733728.