Yikes, I don't feel like Benz has the Software Engineering talent to pull something like this off, which will definitely make me hesitate in getting in a car that runs the OS
The car industry is full of manufacturers who decided to build their own software and failed miserably -- this continues to this day. With the exception of Tesla, very little car software matches anything like CarPlay or Android Auto and that's basically a medium sized feature of your phone.
Those are not any OS, just a basic graphic overlay. OS for instance would be the one communicating to AndroidAuto over bluetooth/usb, and driving the GPU that renders it.