I have a pretty much stock 08 ms3 gt except for an injen cai and I've noticed that my exhaust/engine is louder now than when I picked it up at the dealer, but haven't done any other exhaust/engine mods. Car had 36k on it when I bought it and now has ~44k. Haven't taken it in for a tune up yet, but have had its oil changed once at ~40k. Any ideas?