I put the XPS intake spacer on my 06 Pathy about two years ago. Didn't notice any gas mileage increase, but definitely feels like there is more power in the middle range and I'm thinking it should make it easier to replace spark plugs without removing the upper plenum next time they are due! There are two bolts on the passenger side of the plenum that attach it to a metal bracket. After you install the plenum, the bolts will rest on the top side of the bracket. You "may" need to notch the top of the bracket where the bolts rest to prevent them from pushing the plenum up. I used a 1/4" die grinder with a carbide burr, but a Dremel tool should work just as well.