I fitted the Nextbase 512 to my NC, partly because it has the polarised filter on the lens to eliminate the screen reflections. Dead easy.
Since then I’ve fitted the Nextbase 522 two camera kit (later more ergonomic model) to the Mazda3 (a bit of a pig with some of the trim) I recommend this over the 512, but fitting will be much the same. I did a how-to for the NC with some pics in the first link below. Other dash cams will be much the same, but be aware of possible r.f.i. on your DAB from noisy cheapo power supplies.
Then following this are some Dash-cam pics from when I went to Gaydon