I was thinking of constructing my own custom CAI unit and I've posetd some other posts with questions and such and I'm wondering what you guys think of this. I've heard that there are many bad things that come with an open element unit, I do not know what many of those are and if someone could point them out, that would be great, but the way I see it is I can see them letting in a lot more air that one with an air cleaner assembly. I also know that a lot of hot air from the engine would enter the filter and therefore enter the engine if I did this. So I figure a heat shield similar to the one I posted in the post below, in fact thats what I had planned on doing, a conical K$N air filter with open element, with a heat shield and aluminum tubing. Can anyone think of any drawbacks or negatives to this system, or is it good and should I go ahead and do it, I'm probably gonna do a poll on this topic too.

Heres the link for what I planned on making (the vehicle shown is a miata in case anyone was interested)

http://www.injen.com/webpages/intake.../is6040%20.jpg