I was watching last night on the speed channel, and on the Maclaren the engine bay was lined with 23k gold the guy said it was the best heat reducer or dissipater. Thought that was pretty cool anyone want to try this on there track car lol maybe post the reciept when you finish..

 

I think they also do this with the airboxes on Indycars, they usually put a towel or cover so you can't see it though.

 

The gold reflects infrared radiation best.. For conductive/convection heat, you'd want to have a vacuum behind that sheet of gold...