Doing this myself in my 69 camaro and need a little help!
In the trunk I'm putting one 12 inch wolfer thats already in a box, surrounded by panels coming down on both sides and all around openings. You know like the hot rod guys do in the trunks!

What exactly do you use to make the panels out of once you have made your template, so you can then cover them with carpet or sowhat? I'm not sure what people actually make the panels out of.

Same with the engine bay, when you see people put side panels and back drop panels around the engine bay. What exactly, is that type of metal, or if not metal, what are they made of? Also do they use screws to hold them up? Or something else?

Thank you.

i have seen people use wood panels and then have them covered with carpet. i myself would use a 16 or 18 gauge sheet metal. you can then either use dzus fasteners or pop rivets if you don't need the panel to be removed. dzus fastners are nice, but can be rather costly, but then you can remove the panels with no problems.
use cardboard for the templete. remember, cut once and measure twice.
hope this helps.
bruce