[GTS]

Hi all,
I recently got a SC E90 2011 M3 which also has an active autowerke x-pipe with no cats and a dinan exhaust. Recently I noticed that when I drive in the rain the exhaust sound changes drastically and the sound is no longer smooth. It sounds like a headers leak or something like that... I've already inspected for loose bolts on the connections but all seems tight. The interesting part is that as soon as I transition out of he rain the sound goes back to normal.

Has anybody else noticed an issue like this?

Any help will be greatly appreciated.

Thanks
-GTS