Well ever since I had purchased my 5th gen I noticed a consistant loud creaking noise eminating from the rear cargo area. The noise mainly came from when the chassis flexed and went over bumps.

At first I thought it was the "shock knock " that was the culprit, however after investigation and research I discovered it was coming from the "Rear Beam Bulkhead" part #18 in this diagram

http://www.slhondaparts.com/br...=true

I pulled it out (had to remove rear seat) and lined the areas that it had metal to metal contact with Dynamat. Now my car is silent and has no more annoying noises coming from the rear . So anyway just in case anyone else has this problem now you know what is causing it.

 

hrmm, wounder if you could just remove it and add a strut bar?.. it'd be way lighter