anybody know the best air filter for the imprezza tr ive alway gone with kn

It is an air filter. There really is no best. We can debate that all day, but it is up to you. While u can argue that the K&N flows air more freely than the OEM paper filter, u also must recognize that in the end this will mean slightly more particles wind up in ur engine. The lifetime use of the K&N makes it seem appealing, but given the cost of an OEM paper filter at $10 vs. the $40 price for the K&N, given recommended service intervals, u will be at over 150,000 miles before u make up for ur initial investment in the K&N. And no real studies have been done to prove a K&N makes any discernible difference in terms of power. So go with whatever makes u most comfortable. If u like K&N, use it. If not, stick to the OEM filter.