I am currently running a Perrin CAI with heat shield on my WRX. Just came across the UNI service kit for future cleanings. In some of the intake comparison and performance videos I have seen, one guy switched out for a K&N conical filter over the foam filter, but he was still using an oiled filter. ??? I also looked into a DRY filter should I have a contamination issue on the MAF. Its to early to make judgement, I haven`t had it on long enough. I have not come across any posts or threads with actual issues as of yet.