Fixed flapping, clanking sound coming from rear
 

Started hearing a fluttering sound from the rear of the car at 70 MPH after 2800 miles. A couple of weeks later it also began a light clicking or clanking sound. After owning a WRX I thought that I would never be bothered by minor noises, but for some reason this one was getting under my skin!

Upon looking under the rear bumper I found that the plastic supports for the bumper cover (near the outside aft corners of the muffler) were loose on both the top and bottom. I removed the plastic push in fasteners and replaced them with bolts and nyloc nuts from my shifter kart spare parts stash. I think that I used 10x25mm bolts on the bottom and 8x20mm bolts on top.

Took it out for a trip down the freeway, and thankfully the only noises I heard were coming from the flat four and the Pilot Super Sports.

Did this, still have noise. :(

Thats not good. I expect that mine will be making other noises eventually. :( So far the only other noise I've heard turned out to be my water bottle rattling in the door pocket.