fiberglass?
 

Anyone ever built a sub box out of fiberglass? i wanna make one in my spare tire well, not really sure how to get started though, if anyone has done it before or knows someone/someplace that does it good and cheap, let me know, probably do it myself, but if i can find a place to do it fairly cheap, might just do that.

You can find faq's online on how to do it. Check out Google.com. I have found a few ones on how to make a sub enclosure in the spare tire well before.