I've only had it on for a couple days and we got a little rain. There was no problem with it. I found this on PSC's website...
Q: Does the Hood Louver allow water to get into my engine compartment?
A: This is a very common question that we get asked all the time. The simple answer is yes, some water can trickle down through the louvers during wet weather, but this hasn't caused any significant problems for the hundreds of people who have installed our Hood Louvers. It is important to remember that the engine bay is not a sealed compartment—it is common and expected that water can splash up into there even with a stock, uncut hood. That's why all of the engine components and electrical connections under the hood are weatherproofed from the factory. Many Jeep owners routinely pop the hood and hose down the engine compartment anyhow, to clean off dust and mud after wheeling trips, with no ill effects. Even if you live in an area with wet weather, you can install the Poison Spyder Hood Louver with confidence.
1995 YJ 2.5 cyl. 4 inch Zone Offroad suspension lift on 32x11.5x15 M/T Poison Spyder Customs Hood Louver
Here's mine on my JK. It DEFINITELY makes a difference in the heat down here in the south (FL Panhandle). It was more than a little nerve-racking, cutting holes in the hood of my baby. But I'm very happy with the end result. Poison Spyder seems to be a great company and their customer service is kick-***! Good luck!
Mine....ordered it with powdercoating.
I second the customer service praise. Mine did not ship with the template...very disappointed (wanted to install it right away) I called PSC. They said they would send one out for me. The next afternoon the Fedex guy walks up with the template. Can't ask for better CS than that.
Great product too. I bought it for form and function, but honestly form being #1.