As for the grommet,,,,. Good luck whoever gets next try on it. Two subaru dealers both came to the same conclusion. The parts diagram indicates a "spring"? in the place where the grommet should be. The diagram is vague in its reference to the STI model. Had one of them check the only 05 STI filter he had and no dice either. No grommet in the filter kit. So now i have followed some of the filter delete thread and purchased a reusable filter with a stainless 40 micron screen that has a 6AN size inlet and outlet with a length no longer than 5". Coupled with two 6AN male to 5/16 barbed fitting threaded in both ends of the new filter. Had to do this because the filter used in the "delete" thread is out of stock at the two online stores i could find it at and couldn't get hold of the mfg company via phone or email. Better luck who ever gets this adventure next.