Anyone know if a radiator shroud really makes a difference or is it just engine dressing? I have seen a few different designs for 05 STi. Some seem narrow and others seem like they cover more top space. Any comments?

 

I'm not sure if they really do anything, but the theory as you probably already know is that they are supposed to help direct more air into and through the radiator as opposed to going on top and over the radiator. For the $30 I spent for mine, I guess it's a relatively cheap investment and it can't hurt. I wouldn't spend more than $30 for it though. Check out ebay - sometimes they have good deals, or you can even try making one yourself. It really isn't that hard if you can find some scrap aluminum and a template. I don't think the fat ones really do anything above and beyond what the thin ones do.