you want big thumping bass, just get a bigger setup and dynamat the outer lyings of the trunk, so the sound is pushed back through. There is so much empty space in a trunk, IE inside the paneling, it disspates out. so redirect the sound in your car.
i dont know the material either, but my advise is take it to a pro... headliners are PITA!!!! if you use the wrong chem, the adhesive will detach, then yuo will have saggy overhead