2012 C70 Headliner Failure
 

While driving with the top up, the rear headliner fell from the roof. While this was a big distraction and vision out the rear window was hampered, traffic was light and there was no problem getting the car home.
The headliner is attached to the roof with 8 plastic clip assemblies. One piece of the clip attaches to the roof through a hole and the other piece is attached to the headliner with an adhesive. The headliner pieces, all eight of them, separated from the headliner. This problem has been attributed by Volvo and service managers at 2 dealers to the high temperatures in the south. I live in south Florida. Neither the dealers nor Volvo has offered any compensation for the required repair. One dealer offered a repair by replacing the clips at a cost of $650 and the other dealer stated that the headliner would have to be replaced for over $1000.
So....upon an analysis of the detached clamp pieces, I found that a fundamental mistake was made preparing the clip for attachment to the headliner. It is standard practice to "rough up" the surface of parts that are to be attached with adhesive. The clamps on my car were smooth as glass. There was no evidence of adhesive on the clamps, proving the failure was due to improper surface preparation and not high temperatures in Florida.
If you have this failure you can reinstall the clamps yourself. They can be located on the existing footprints.