Car Will Not Start problems of the 2007 Nissan Altima Hybrid

Have problems with car going totally dead, no lights engine won't start etc. Had battery replaced but this was not the problem. Car still died a couple more times until it finally would not start or function in any way. . . No lights (not hazard,brake,etc. ) would function,engine would not start, nothing. . . Car is dead. Towed to dealer first told it was the body module component? one of the brains in the car. Then informed that this was not the problem. Told today it is the wiring harness and will cost $3,500. 00+ this in my opinion is a major safety issue especially as we commute in this car. It could have died/stalled on the freeway with no warning and no ability to use hazard lights,etc. Would not even be able to move car with dead engine if we were capable of doing so,meaning if we did not suffer an accident due to this electrical issue. This should be noted and people informed of this danger! would like Nissan to take the car back!! I cannot believe that there has not been any complaints about this failure. This is dangerous. Life threatening as far as I am concerned.