My 2006 Toyota Prius shuts off while driving. Multiple potential reasons have already been checked. The car has a GPS interrupt device installed by the dealer.

This happens while driving at 35 - 45 MPG. Tried to reproduce the situation by quick acceleration from stop and even driving at freeway speeds for two hours. I could not reproduce the situation. When the engine shuts off, the dash lights stay on the steering operates correctly and after I coast to a stop I can instantly restart it every time. There are no dash warning lights and when checked there are no service codes that show up. Also, the tank had plenty of gas each time the gas cap was tight. Battery connections are tight with no corrosion. Again, there is a GPS tracking unit/interrupt device installed on this car by the dealer who sold it to me. The interrupt device should legally only be connected to the starting system but it may be connected to the ignition and is cutting it off. The finance company shouldn't be doing this to my car because I have not been one day late on my payment and if they are doing this, it should only be affecting the starting of the car not cutting it off while I'm driving it. There has been many customer complaints that their cars have been intentionally shut off by the GPS tracking/interruptive device while they were driving or the car was sitting at idle according to the New York Times. Could the alarm system be shutting off the ignition or cutting off the fuel supply and then why am I able turn the ignition right back on so that I am able to drive the car normally after that happens?