Here's my 2 cents on this subject.
The PZEV may run hot, but there is no way that it can rut hot enough, under normal conditions, to cause any damage to the paint on the hood, even long term.
I used to have a '94 Mercury Sable that had a severe overheating experience, and I mean SEVERE, like, just short of catching fire. It was a 108 degree day one summer and the water pump gave out. I was in the middle of nowhere, with no cell phone, and someone else's kid in the car with me... so I continued driving to the nearest gas station, which was like 6 miles. (I should also mention that the car was under an extended warranty) By the time we got there, the cooling system was dry as a bone, and the heat coming off the engine was unbelievable. It ended up warping the aluminum heads, etc etc. My point is... even with this kind of extreme heat, the only damage done to the paint was a dime sized area directly over the engine that kind of did that paint cracking thing. It wasn't even noticeable unless you knew it was there.
So I seriously doubt that one of these engines is going to cause any kind of damage to the paint on your hood because of a lack of insulation, at least not without some kind of engine malfunction first. So just relax. If Ford thought it needed insulation, it would have provided insulation.
I love this Tiburon but would give it up in a heartbeat to have my 2002 ZX5 back...