Total shutdown...

I have a 2007 chev. Cobalt and recently while driving@ highway speed the vehicle totally shut down (motor, lights, radio, anything electronic) I was able to restart the engine with all electronics restored. I took it a dealer they told me that the problem was caused by a malfunction of the Mass Airflow Sensor. We have been to a GM Dealer Twice. My biggest concern is that this car may not be safe to Drive and here is Why: When the "TOTAL" Shut down Happen we were rounding a left hand curve,we were Lucky and Managed to grind the car to stop without sliding off the road. After sitting in total darkness for a few minutes ( without any electric at all) the car started and acted if there was never a problem. The next day we took it to a GM dealer all they said was the Mass Air flow sensor was bad after repair they said the car was safe to drive. When questioned about the total electric failure all they replied is the sensor caused problem and there was no electric wire damage. It seems to to me that if this sensor can cause such a "MASSIVE FAILURE" of all electric systems required to bring the car safely to a stop, this car may have a major problem. After spending  $400+ it appears that the Air Sensor was not the problem. The shut down happened again-As my son was entering a Busy Intersection tonight his 2007 Colbalt shutdown again. Last time this happened (couple months back) a the GM dealer assured us that they fixed the Problem, I Say "BS." My son almost got T-boned this time as his car came to a halt in the middle of the intersection. It appears to me that these cars are Dangerous but I guess someone needs to be killed before any action will by taken by GM. Went to the GM dealer again after a total shutdown, (at the direction of GM headquarters). The dealer was great - they checked everything: Connections, Fuses, Wires, Wiring Harnesses, and the Computer Diagnostics (all on our dime). They found nothing wrong. I called GM Headquarter's back, was told SORRY FOR INCONVENIENCE but no codes were displayed that they could not help us. After a hour or so of of heated conversation they agreed to monitor the car( a device was installed to record data when the car shuts down again) IF this problem is worth monitoring GM should be doing it at their own risk and not at the RISK OF INJURY to my family. Come on GM DO THE RIGHT THING BEFORE SOMEONE GETS KILLED!!!!