I've never seen this posted here, but apparently Nismo Japan makes this optional gurney flap for the factory wing on 2015+ Nismos:
Taken from
Nismo 2015 Parts catalog
Price? 138,000 yen for the wing and an additional 10,000 yen for an "attachment kit"
Look Nismo Japan . . . ur cool and all, do great work, but over $1000 USD for that tiny *** addition is ridonkulous.
Not looking to get one or anything, just digging around and came across this.
Kinda surprised Carbon Signal hasn't come up with an add-on like this (bigger) for the 2015+ Nismo.
Enjoy?
EDIT: Can't edit the typo in the title, can a mod help?