First, I will argue against nothing being said in Manufacturer's Data
But the mounting of the Nextion device screen in its final design is indeed user responsibility.
Mounting without a bezel? Does this also mean that the touch sensor flex cable was left exposed?
- if the flex cable was protected, then why not the remaining?
I might argue proper mounting ensures Nextion device is not free to move but actively prevented.
- As described, shock from a drop would also present the chance for the Nextion to escape the casing.
Sorry to hear, but the Datasheets are indeed not hidden (just above Order Now)
Most cars (at least in our country) also have a power source available when the vehicle is off,
and as such cooling to maintain within spec is not an impossibility.
When the ambient exterior temperature reaches 70 C, then no one is left to worry about it.
What country has ambient air temperature of 70 C?
In my country (where in-car temperatures may also temporarily exceed 70°C if parked in the sun and A/C left off), Renault, one of the principal car manufacturers here, was one of the first to put massive LCD elements into their cars' dashboards. Already more than 15 years ago, they solved the temperature "problem" with small peltier elements to maintain the temperature below a certain level and with small dimmed light bulbs at the lower end of the temperature range. All you need is a thermocouple and a bit of logic.
No need to reinvent the wheel :-)