The more water you get under the hood, the more chance for rusting parts also. I put a vented hood on the summer car to release the hot air from the headers, and it works great...like Stazi said, you can see the heat billowing out. I now have other issues though like water collecting in crevaces between things after it really pours.
Has anyone cut out flush 'subaru' style vents into their stock hood? I was thinking about looking for a junkyard hood for experimenting with this ...cutting holes and then putting some mesh underneath. Also, I heard people were taking out the rubber liner at the top near the firewall to help release heat. I do know since I've removed the hood liner, the temp guage stays lower than it used to...although the hood heats up quite a bit more.
