i stop using CAI already. cause of things like this...its too much of a risk for not much performance gain...i mean i really cant feel like immediately gaining so much or anything at all when i installed the CAI...im not saying its useless, im sure it serves its purpose, just that the gain isnt really so drastic.
somore must cut hole in bumper etc..if route to lower part fo bumper where there is a grill(if possbile), might be too low and risk sucking in water... haihs...so i stop using it. if really wanna go all out, just get a vented bonnet, air scoop, and channel cold air into the engine bay.
and about plastic bags, it can get pretty nasty if it sticks to your radiator, exhaust, or even manifold, becareful guys... try to avoid if possible...