I was just curious if anybody else experiences the same issue. I've checked around but couldn't find a definite answer. Mine is a 08 Impreza hatchback 2.5i basically stock. When driving with Windows up I can loudly hear the boxer rumble sound which is nice. But I'm wondering if that is normal. From the outside I can't hear a rumble from exhaust then inside it's clearly there. I've checked the floor boards and nothing stood out, like holes or anything. I was wondering if maybe it could have something to do with why car is hesitant to accel while shifting heavy footed. I haven't had a chance to check the plugs yet but engine does have the slight knock I've been reading about. Please let me know if anybody has any other opinions then what I've found in the forums so far. That would be greatly appreciated.

DC - noobie