I'm in Northern California...so I havent had that much rain yet, but a week ago while driving in the rain all of a sudden the exhaust note of the car changed to sound like the header fell off...and there was some vibration I could feel through the shifter knob. However, before I could pull over and check things out, it cleared up. Then today while driving my WRX during heavy rain it reoccured. And again it cleared up as I drove into an area where the rain wasn't coming down as hard. Anyone eard of something like this? any suggestions?