Anyone can make a square or a flat piece to fit on a flat surface (well, almost anyone)..
The trick is to make something like a cold air box fit in a volume made up of compound curves.
I spent a great deal of my youth building and designing model aircraft, and picked up a few tricks here and there.
One of those tricks happens to come in pretty handy for automotive work, as well..
So, I just wanted to share my incredibly simple way of duplicating a compound curve:
* a bunch of bamboo skewers
* enough corrugated cardboard to cover your project
* a pack of Camel cigarettes (as evidenced by the illustrious picture below)
* some sort of a marker, like a sharpie