http://www.singularmotorsports.com/product/singular-motorsports-na-miata-hood-louvers/#
$189, made for Miata so no cutting the supports under the hood but I am ok with doing so on my stock hood already drilled for hood pins.
I can see if they will just sell the two outer ones instead of all three parts and will look at the NB and NC Miata versions a bit closer.
I would also do a cleaner looking wickerbill with curved ends, easy mod.
I want to get a vented CF hood but with buying it, shipping, painting, it get's pretty costly and I am retired but if I sell more stuff before long I might get one anyway, I could always sell the vents if I swap to the CF hood.