I used that Airpuxem camera on my 2016 Mazda3. At 170 degrees it has almost too wide an angle of view, and care is needed in aiming it to minimise the classic wide-angle barrel distortion in the useful part of the picture. A 140 degrees camera might be better.
It replaced the previous obsolete make that suffered from condensation inside the lens. That Mazda3 uses the same hole profile in the boot-lid tin-work as for the plastic blanking plug on the MX-5 NC, but slightly less complicated surgery needed (Junior hacksaw and file) on the CX3 camera bracket I actually used, plus some packing. I’ve added some pics to my review for the Airpuxem.
I used a step-up converter from the 6V supplied from the head unit to give the camera 8V, but it’s not needed on the NC. I had to trim the leads to be short and tidy with relevant plugs and sockets as part of the boot loom.
I used a similar camera in my 25AE NC, but here took the 12V from the reversing lamp. The clever bit is using a slightly greater diameter umbilical to the boot lid, so it looks OEM with no leads added on.
Inside the car is an exercise for the student and depends on how one accesses the display, just make sure there are suitable plugs and sockets to allow removal or fault finding, as here in the NC.