Espace IV Radio coverage – Workaround

Since I am certainly not the only one whose radio cover, i.e. the middle flap over the glove compartment bulges upwards, I wanted to ask if and how sufferers have solved the problem. My friend has removed it with his method -completely and glue in- unfortunately only smeared up. I glued back with Pattex, it is now better, but everything is far from satisfactory. At the edges it is still arched and without fumbling on the upper edge the Abd Now I could get to a used but not curved flap relatively cheaply. Does someone know how to change it and how to prevent the “new” flap from arching again? My friend once said that you could try to completely lower the surface, scrape the foam under it and put it all back on it… Someone’s idea? I love the car, but this cover still brings me to the grave…