I used cheap shitty wrap and a can of hi temp paint on my 2wd manifold.
It did wonders for underbonnet temps, you could actually hold the manifold after a run whereas before if you looked at it it would burn you.
It was on there for a couple of years and didnt crack, it did start to perish so i took it off and had the manifold ceramic coated inside and out.
This is nowhere near as good in my car so i will be re wrapping it with carbon wrap.

I did also wrap my whole exhaust system up to the back boxes with the same stuff, this didnt perish but did cause the exhaust to crack on a Y join, where it split fom 1 to 2 pipes on the sharpest point it cracked.
I will redo this aswell and not sure what i will do with that section as it will just crack again.