What is this part of a car called?

A thin adhesive pad that I assume attaches the headliner of my car to the inside of the roof has come loose and attached itself to my moonroof cover, freezing it in place. I am going to get it fixed as it is under warranty but want to sound smart when I describe what is wrong. So does this adhesive pad (looks sort of like cheap carpet padding) have a specific name or is it just called the thin adhesive pad?

It appears to be spray adhesive. link

Unless you mean the “foam backing” referred to in figure E of the link I gave above.

Thanks for the link. I do mean the foam backing, which is very sticky on both sides, evidently due to the spray adhesive. The dealer is not going to be very happy. I looks like a difficult and expensive task to perform.