Stumbled across this full kit whilst randomly browsing.
Fitted today. Really easy with excellent instructions that include step-by-step pictures.
Sounds great so far. Not had time today to fiddle with the settings.
Took about 4 hours to fit.
URL for the kit:
http://r35audio.com/product/370z-subwoofer-kit/
I've ordered a cheap rear mat to cut a hole for the sub to show through and some edging to make it look semi-professional!
https://www.bootliner