[2006 LR/RR/SC - FULL SIZE/JAG/4.2]
Removed cover as part of maintenance event and the insulation attached to the bottom side was completely falling apart and literally disintegrating. Doubt that’s a replacement part? So if not, anyone have a recommendation for another material that I could replace with? **appreciated**

Mine was the same, made a hell of a mess when I removed the cover.
The insulation is not available, but new engine covers are, but I did not like the price.

So I am using a 10mm sticky back foam that is foil lined, from ebay, I also used some aluminium tape to cover all the gaps.
I've not fitted it yet but when I do I will keep a very close eye on engine temperatures, if they rise I will strip it out and use the cover with no insulation.

David Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Or just leave it off like I did because superchargers look better than plastic.

Hi. Cleaned all the charred gunge off mine. Gort some sound deadening insulation foam ( sticky one side - foil the other ). Fitted to the cover a few months back. Very quiet now. ----------------
2010 RR tdv8 3.6 ( gone but not forgotten ...)
2012 RR tdv8 4.4
2004 RR 4.4 V8 (M62) -gone but not forgotten (sob)
1998 P38 RR - least said the better
2009 BMW 7 Series 3.0d
Various motor cycles - BMW GS
1998 Jag XKr 4.0 V8