Pff, that looks ridiculous. Show me some serious testing of engine bay temperatures for equivalent ambient conditions and road speeds and I will believe it. Just get an effing hood scoop if you think it's that big of a deal. I'm sure it'll outperform a tiny gap on the rear of the hood. It's not even closed back there stock anyways...
Edit: as for the article, I'd like to see their testing conditions. Road testing really doesn't count unless everything is completely identical and they did multiple runs. Dyno cruising with a fan and controlled temp/humidity would be the way to go, unless someone knows why this is wrong?