Any alternatives to engine cover insulating pad?

[PaulGover]

The foam pad under the engine cover on my 2.7 TDVi has disintegrated. Originally it was an integral part of the cover, welded on at a few places; now it's bits of tatty foam and a lot of dust

I see new covers are available at £200 or so; I wonder if there are any safe alternatives - I looked on the Internet and found a lot of foam insulating sheets, but I suspect they (a) might not like the heat, and (b) might not compress well over high spots (a lot of them were "closed cell" which I think limits compressing the foam).

Of course, it could be something wrong with my engine causing the foam to disintegrate, and part of it I think is mice nesting, or even squirrels hiding their nuts, but the car is coming up to 15 years old, so I guess the foam is allowed to show its age...