The keywords: I UNDERSTAND.
And I HAVE to say a VERY important thing: Windows 8 IS NOT a real time operating system. If you expect that the program should also control the car itself, Windows 8 IS NOT the right answer. In Windows 8, it IS NOT specified, how fast the system (and, concequently, all the programs for it) will respond to user's command. For controlling the vehicle itself Windows 8 IS NOT an appropriate system. Use a REAL TIME OS for that, like QNX.
If the application is not so important (just turning audio on and off, and so on, without direct influence on the car control system), then I can agree to write this program for Windows 8. Otherwise I cannot.
I don't quite know, what do you mean by a very exprerienced C++ programmer. I wrote different stuff in C++, and did some other things, like writing mp3 support for an old program. Is there a test task, or how can I prove, that I am experienced? I can't upload all of my work here, because I didn't ask my customers for their permission.