I finally made my CAI on the weekend ( El cheapo PVC version). after it was in i went for a spin round the block, and to my disapointment, didnt really notice a difference in performance. but on the way to work this moring, i gave it a bit and thats when i noticed the difference, before i put it in i only ever really noticed the flatspot going up hills, but it is almost impossible not to notice it now, but i must say it i love the note it makes at about 4500rpm,