Do I understand correctly that the motivation for this is that the rear-view camera on the Chery Exeed LX runs Linux? Is it a good idea to ship a car with safety components running Linux?
Linux (as in, the kernel) is extremely stable and well tested.
If the components in question utilise any significant features of the kernel, I strongly doubt some homegrown kernel-esque project will achieve more stability and reliability than Linux.
Sure, if it can be done with a (minimal) amount of embedded code then it quite possibly should be, but if a whole kernel is actually needed then Linux is a fine choice.
E.g. new Mazdas have a Linux distro with DBus communicating between binaries and Opera browser to show UI. The actual UI is written in JavaScript and HTML.