Looks simple to make with a piece of sheet metal and a couple after-market electric radiator fans to operate with a certain temperature or be switched control. A couple of louvers on the hood to vent the air .....and wow that looks "cool" so to speak..
I think I just found something to do in the extra time I find. Customize it and make a one size fits all...hmmmm
Both those cars are MR2s, right? They probably fabed up that set-up because it is harder to efficiently supply cool air to the engine in the back. That would more then likely be overkill in a standard car with the motor in the front. Granted a vented hood on a Saab would be sweet, just like Yankton's.