Thats right it is raised up. I had the oppurtunity to do it with some spacers a little while ago and had some extra hands to help, so I got it done. The idea is to help release the heat built up in the engine bay. Its an old RS Turbo trick (Ive had a couple in the past), theres a couple of tuned 180's on other forums who i've seen since with the same mod.
All it can do is help when I get a bit more involved in engine upgrades. Its quite subtle and I feel its a good alternative to a bonnet vent.