im not sure where to start on this - the topic has been discussed thoroughly in various threads already - i'd refer you to them by suggesting you search on here for them.
but, to summarize:
- hood insulation is, by design, a flame retardant. resting on the engine will melt it but not incinerate.
- the primary function of this insulation is to dampen noise, not suppress engine fires. as such, it is not necessary. I removed mine, and enjoy the increased engine noise. Some people argue that the heat that your paint will see will cause degradation of the paint - unless you're in a hot climate and are perpetually heatsoaking your engine, the heat from your turbo with is located below your engine will not harm your paint. if this is a concern, i'd recommend getting a turbo blanket because this would insulate the hottest part of the system.
- if you're adamant about having this insulation, you can buy an OEM one on here, a dealership, or any number of online vendors. aftermarket ones are also available.