I think with putty and paint you won't even need to fiberglass it. Use the putty so you can "lose" the wood grain and paint it.

I would put a lid on it since heat rises, should help draw cooler air from the outside.

No lid needed if you put a seal around the top so it contacts the hood.

Update: The temps are now decreasing while driving, while before with the HAI, the temps continuously increased.
I am seeing 10* or less above ambient.
With HAI, the temps were 30* + above.

well i might just have to build one of these lol

It's a 4" 90* rubber elbow, only found at specialty plumbing stores or online. Lowes\home depot have 3" only. I actually have it cut n half, works nicely. About $28 for it.

my 3" pvc pipe makes the cone more centered to the right of where it should probably be, but o well its ok for now.

You gotta see that I have a different tb on there (N*) as well as an aftermarket maf setup (zzp 85 mm).

wood FTW!! *thumbs up*

Added some pics, fiberglass started.

I hope you plan to smooth that out. I still think a liberal coat of putty and some primer and paint woulda been easier.

It was a rush job.
I am definitely going to work on it.
Didn't have the time when I did it.
I wanted to reinstall it so I can keep intake temps down while tuning.
It beats the heck out of the plain ghetto plywood look!

Finished.
It's not perfect, nor is anything else in the bay.
I was tired of sanding and over this thing.
It'll do the trick!!

Looks good Steve, personally I liked your FWI the best but this is a close second.

I did too, wish I never sold it. It just looks soo open in that area with a FWI.
Needs a turbo, lol!
It would be smoother, I may touch it up some, but I used bondo glass instead of bondo without glass, pita to sand.
I didn't bondo the inside where cone comes through. That area I can see, and it looks rough. I need to touch that up again.