Looks awesome, these always remind me of someone wearing a cap.  This is heaps cheaper than a US company was asking.  At 300ish its worth a shot.  Put up some photos of it once you've finished finessesing.  

My attempt at fitting it would involve a hammer ,blue tack and no more nails  

Spoiler is from Ebay, currently on special. It does look fantastic, and it's a real carbon fibre, not a vinyl wrap.. Regarding fine adjustments, there is a concern that small fibres may cause complications similar to those of asbestos so I'm getting a full face mask and disposable overalls. https://www.ebay.com.au/itm/CARBON-FIBER-CS-TYPE-N-STYLE-TRUNK-WING-REAR-SPOILER-FOR-NISSAN-370Z/262399870438  

Looks a pretty damn close fit and so much better than the stock spoiler. Work wheels look great too, very tastefull mods. Got a link to where you ordered your  spoiler from?

It's a no-name brand, but the quality of workmanship is pretty good. I don't see many classic hand-laid-carbon-fibre faults. It didn't come with any instructions, screws, tape or paper templates. I don't recommend fitting it yourself as it is really time consuming for a beginner (me). But I already started so... OK, trial fitting (screws only). Middle part fits well, the RHS needs minor adjustment (2-4mm) and the LHS needs probably at least several mm. The problem is that it needs to be ground exactly where one of the 4 main screws is. I'll try on the weekend.