I used a sheet of ACL heat shield and bent it into shape to suit. As an indication to how good it works, I once went for a good hour drive to the track on the highway and got out to check the engine bay out...I touched the heat shield material straight away and it was warm, not extremely hot that it could burn my hands. Engine bat temps were pretty good too. The good thing about this stuff is you can cut it easily with aviation or tin snips and bend / beat it into shape really easy too.
I give it 5/5 stars.
Here's a link for more info on this material: