Trying to identify material in rear trunk

[Monster Poodle]

Fixing up a 99' Boxster after it suffered a serious mouse infestation. The issue I'm having is the mice ate away this foam material that is under the electronics in the rear trunk. See pic...

I want to replace it, but have no idea what it is or where to find it. If there is an alternative material I can use that is commercially available, that would be fine with me.

Thanks in advance to anyone who can help!