Guess I know what I'll spend a tad of my time tomorrow doing. It only took me 5 minutes earlier today to install the K&N that I bought 2 years ago for my GT & drove no more than 500 miles on it before I installed the CAI w/ new filter. Then I put the K&N back in its box & left it in my parents' attic for a long while. I took it out of the box today & it still looks brand new & is now in the Mach.