Need ideas for interior trunk panelling.

I want to make some custom panels inside the trunk for the back, sides and floor so i need some ideas.
Keeping in mind I have a fuel cell smack dab in the center.

Any ideas would be helpful so I can kick them around and see what might spark my interest.

I'd like to go to the stereo install shops that build all the trick stuff for the guys who turn their entire car into a concert hall, but I don't trust leaving my car with ANY of those knuckleheads.

I was thinking just gluing down some black carpet pyle but I'd like to build some panels for the sides also.

Tell me if this is stupid:

Was thinking of cutting some thin particle board to build the panels then just covering them with carpet pyle, but I'm no upholstery guy so any ideas welcome.

I was also thinking of ordering some trunk spare tire covers from the dealership and cutting them and piecing them together until I have something I can work with....dunno.