would this work at all?

Sure it would, but it seems a hole lot easier to do it with Lexan (polycarbonate) which you can bend with a heat gun and use other standard woodworking tools and the like with.

Cheers,

ok but what are the physics behind it. what else should i know? i have the stuff sitting in my shed to go do this right now

Physics? You're trying to isolate the intake from heat. No physics involved. Build a wall.

Fiberglass would be my last choice of material. I think I'd go with wood or cardboard first!

What about all of these home made ram air systems what all is involved with that

All of what home-made ram airs? Here? There aren't any yet. But a couple in the works.

What all do i need to know about building one?

You want to catch some air, compress it, and stuff it down a pipe to where you need it.

What are you asking for here? This is a custom setup. Do it however you want. There aren't any instructions. If you've been reading performance, you know I've been working on one option. I'm still a couple weeks from bolting it onto the car.

Read up as much as you want, then try it. Do it your way, my way, or any other way. Your preference.

The idea is to provide more cold air volume for the filter to draw from.

Thank you thats all i wanted to know

I just added info to the post above while you were replying. This is a totally custom setup, and varies by application and personal preference. There is no ONE right way to do this.