The reason most insurance companies total out a flooded vehicle is because they are on the hook for any future damage related to the flood on the same claim. Things that work now may quit working in a few months and it gets expensive for the insurance company to keep paying to have things fixed. So they often total the vehicle and sell it at auction to recoup some of their loss, but once it's sold at auction it's no longer their problem. I sure as heck would not want to keep a vehicle that had been flooded and would be strongly encouraging my insurance company to total it.