Re: It'll never work
Every OS needs to reboot to apply OS updates, because no modern OS can replace code running in-memory (they can replace code on disk), so a reboot is the only way to not have existing running processes running old code.
To give you a sense of what a massive undertaking a no-reboot OS would be, if the OS is executing such instruction in the program text with such state, the update has to provide a way to go to the equivalent instruction in the new program text and a way to convert state.
The problem with Windows is that reboots take so long, that they are practically holding the system hostage (for 15 minutes or so). When the Windows 8.1 update rolled, I clocked a full 35 mins of downtime on some systems (for an update marked as important).
But anyway, I am sure Renault has at least a pair of systems, and they run them in a highly available fashion aka when one is rebooting, the other is still up.