Nuts! Don't people value their vehicles? There are cheaper ways of having fun without risking a £40-70K vehicle!!
The thing is many people don't realise that if the water enters the passenger compartment it will in many vehicles, play havoc with complex electrical systems. A quick splash through a ford shouldn't present any problems but as the video shows there are many people who have a rather cavalier attitude to risk assessment. It's either that or they just have zero awareness of the dangers.
Beware, the engine might still be working but electrical components that are often located under the carpets, will rapidly become effected, causing all sorts of weird anomalies that will end up being mega expensive to rectify. Such damage may even write off the vehicle. Door seals may help to slow down water ingress but in reality it will get inside regardless. If you want something that's watertight then buy a submarine not a car.
Personally, I try to avoid flood water if at all possible but on those rare occasions where there's been no alternative I have taken the following course of action:
1.Enter the water very slowly with the drivers door open. That way you can keep an eye on the precise depth. Keep the door firmly shut if other vehicles are causing bow waves. Peer out of the open window instead although you won't be able to gauge the depth quite so well.
2. If the water level gets anywhere near the top of the sills then that's quite deep enough.
3. Keep the engine running at all times to avoid the water entering the exhaust system.
4. If in doubt back out.
Others might have different preferred methods. It doesn't matter what they are as long as you and your vehicle emerge unscathed.
IMO it's always a good idea to know at what level your air intake point is located.