yeah, it's mainly the filter and the airflow. most ebay designs are almost exactly like the AEM CAI. any reason why you want an CAI over a SRI, or a comptech icebox? Is rain a big issue? .. i mean if it really does make a difference.. you're only getting an extra maybe 1 or 2 hp.. which isnt really much once you think about it. there are more important things such as suspension or whatnot.