I just bought a camera that replaces the right licence plate light. It fits perfectly and is listed as a backup camera for a Nissan Livina. It fits the 370Z as if it was made for it. I purchased mine here:
Color CMOS/CCD Car Rear View Camera for Nissan Livina - Tmart.com
I found the video quite good, and will be returning my Boyo VTL 422C, as I felt it wasn't as good as this particular unit.
It is about 1/4 the price to boot!