BACK-UP camera, for 370Z Touring with OEM radio, DVD, +9G HD, NAV., Bose...

Shootpetoet

I want a working BACK-UP camera, for my 370Z Touring with OEM radio, DVD, +9G HD, NAV., Bose, bluetooth, video and audio + USB-connections, ... .
Driving my new Z for nearly a month now. Searching the net and car-shops for a (working) reverse-camera.
Seems the answer is not yet given here, though it came up a year ago, or so.
Or was it already answered? I don't plan on getting rid of the original sound-and-nav-system. Not planning on installing Kenwood (or other) brand of systems to replace mine.
And I want a better answer than what I got from the Nissan factory: "No! You bettah no do no work on car-electronics, after buying it, please! Thank you, bye bye."
Thanks in advance, reader. To let me know, what is needed to get the screen to swith to 'rear-view' when in reverse. Nothing more. But nothing less, too.
Much appreciated.
Yours,
JK (Belgium) [that's with a rear-foglight]