Headliner fabric has a special foam backing on it that will mold to the contours of the vehicles roof. A headliner is the “ceiling” of a vehicle. Step 2 :Find a good, large, clean area to work, lay the headliner face up on the table Nest, spray the strong glue on the strip about 6" wide down the middle of the headliner, have a friend hold the materials up above the headliner while you use the plastic paint guide to smooth the materials on to the glue.