Fibreboard dude, B&Q will have it. I havnt done it yet, but I will be making some up for my girlfriends mini. Pretty easy in theory, its really just a big rectangle! I've done my rear cards though, with speakers built in, and they are in fibreboard.
Fiberboard! That's it! I know what the stuff is but I couldn't think of the name to search so I just pulled up the wall board. I've got no B&Q here though, just Lowes and Atwoods (I'm in the central US). They've gotta have some at one of those places.
EDIT: Can't find any listings for fiberboard on the Lowes site. I might just have to check out that hardboard wall panel anyway.
EDIT 2: Well, it pulls up particle board, but usually the stuff they sell is way too thick.
EDIT 3: Hardboard is a type of fiberboard:
http://en.wikipedia.org/wiki/HardboardAlthough I'm still worried it won't be flexible enough.
Edited by jmetal88, 25 July 2009 - 12:12 AM.