Cloning the storage, or any other file access, no longer works with modern devices. For example, last time I plugged my phone into rental car, I got two easily

Cloning the storage, or any other file access, no longer works with modern devices. For example, last time I plugged my phone into rental car, I got two easily refusable prompts, to access contact list and to access files. Damaging the device is a real deal -- I'd think more by accident than by design ("we spilled some soda on this charger... so it now gives out 20 volts instead of 5). That's why I used to carry a small USB voltmeter with me when traveling.