I just installed an ebay "Nissan Livina" rear camera last weekend.
Sony CCD Car Camera Nissan Livina Cube GT R Pulsar Versa Fairlady 350Z 370Z | eBay
I went with this one based on numerous mentions here about it. The way it is made to replace the license plate light makes for a clean factory look, and it is almost not even noticeable on the back of the car.