Passenger seat rattle

[bhpilot]

Hello all,
I recently traded in my 06 for an 08 Alpha. I seem to have a problem with the passenger seat back as it rattles(seat empty). I see we had some old post on this problem but missed any real way to fix it. I have been to the dealer twice but no help. They tell me they torqued some of the seat bolts but don't really know how to fix it. I can stop the noise with a short bungie cord from the head rest rail to the back seat pull up handle, works great, but looks like crap. If anyone has the fix please post. Seems like the seat back needs to be shimmed or something. By the way I got a loaner Alpha with 400 miles on it, it had no rattle but had low miles.Please help. I love the V-8 and gas milage doesn't seem all that bad.
Thank You for your time.