Sand is a good heat insulator. It may take a very long time before the car cools down enough that it doesn't catch fire again once re-exposed to air. I don't k

Sand is a good heat insulator. It may take a very long time before the car cools down enough that it doesn't catch fire again once re-exposed to air. I don't know why Tesla doesn't recommend submersion. Here's a Dutch solution - a water container for storing a car for 24 hours while it cools down. https://www.techeblog.com/bmw-i8-water-container-firefighters/ https://www.techeblog.com/bmw-i8-water-container-firefighter... Looks like it also needs a crane, and is done after the fire appears to be put out. We had some car fires here recently (arson, alas). The smoke can be toxic. We were advised to close our windows. Best there to put it out rather than let it burn even in a fire-proof box. The fire-proof box still needs cooling.