Anyone know of a real Ram air not just a cold air kit. or even a home made one with a 3in hose running down under the front bumper similar to a march one for a mustang?http://www.marchperf.com/pg31.html#95ramair

You have a 4wd, why would you want it under the bumper? Putting it under the bumper would cause it to suck water. The closes thing to a ram air effect I can think of is the snorkel used by some people and that goes towards your roof.

They Provide Better on Highway gas mileage and some minor highway performance gains both of which are desireable to anyone with a 1st gen. any water sucking is minimal and won't casue damage provided your smart with it and not submerging the inlet ie crossing rivers.

To be honest with you, ram air is worthless at speeds that Xterra is able to achieve, whether safely or not.

The faster you go, the more positive effect you see. You won't see any difference going 70 mph, it's just not enough. Risk of sucking water in is not worth the minor differece you "might" see, but I doubt there will be any.

Also to answer your question, I have not seen a true ram air kit for the X, there's no market for it.