So I have a crewcab that does not have a headliner. I am going to be installing a sound system and sound proofing the whole thing and, since the sound deadening calls for 3 layers of materials, I am wondering what I could/should use for a final covering in place of a headliner. I am worried about bumps/lumps being formed by the use of CLD tiles and seams that will inevitably occur during installation of the other materials. I know crewcabs are a bit rare, so this problem doesn't come up often, But I would appreciate any insights or ideas anyone has that could help.