The Track Spec Motorsport hood vents are a proven modification that works and I give them a lot of credit for coming out with them and manufacturing them for our vehicles. Engine water and oil temperatures will drop about 10F-15F while street driving and at least 15F-20F on the track. You will feel the heat pouring out of them when you are at stop. Thank you Rusty for helping the Z community with the water/rain shields rep for you.
Even with the water/rain shields installed you will see an improvement on the street or track. Also the current market price on sheet aluminum is not cheap.