2008 Chevy Tahoe tape required on dash and 3rd row seat

I just purchased a demo Tahoe a couple of weeks ago. I began to notice a rattlling noise that sounded to me like it came from inside the doors. Under warranty, I took it to the dealership and they confirmed the noises were there and said the fix was to apply some kind of tape to the third row seat and in the dash. My concern is why would a car this new require tape and how long would this type of fix be effective? Have I purchased a car that was not put together well and have a reoccuring problem on my hands? Thanks.