Problem

The interior ceiling hangs.

Ceiling

On Berline the ceiling must be taken out through one of the rear doors. (On Break the ceiling can easily be taken out through the tailgate, but here it is rarely problems with it.)

Tear off and scrap away the foam with a wire brush.
Glue on with glue that does not smell, for example 3M spray adhesive. Contact adhesive is not recommended. Floor adhesive may also be used. Do not use too much glue (it can go through). Place plastic bags with water on top of the grooves to gain steady pressure. (Use two bags inside each other to be sure to avoid leakage.)

Before installing the roof again, consider whether to add up more wires (reading lamps for rear passengers, speakers etc.). Also if you want to soundproof. Thin asphalt plates can be used, but be sure to secure them well, and be aware that they may give off a smell when the car is in the sun. You can also add a layer of eight mm fireproof felt, this will make the car less hot in the summer, and perhaps soundproof a bit too.

You can use many types of blankets the new ceiling, but they must not be flammable. A thick woolen blanket might be good.