The First Flood Car Tips is Turn Off your engine, or else your engine would burst and a lot of parts of your engine would break and you'll need to spend a lot of money to repair it or even worse replacing the whole engine.
The Second Flood Car Tips is Unplug the car battery never leave it on in a case of Flood, because if the water reaches the electronic parts while your battery is plugged, it will short a lot of electronic equipments of your car like your radio the clock and one of the most important part of a car which is the computer box, believe me you don't want to have a short circuit on this thing for it controls everything.
The Third Car Tips is Release the Hand Brake if you don't want your car to be stuck.
If you've successfully comply to these 3 simple steps then your car is saved even if it is flooded, all you need to do after the flood is change engine oils and filters, drain your gas tank and fill it up, dry the computer boxes and other electronic equipments before plugging in the battery, and a complete interior detailing is surely needed, drain and clean headlights and tail lights, give a car wash then your car is good to go.
Flood Car Tips