I noticed a rattle coming from the passenger rear a few days ago (bought the car a week ago tomorrow). Tonight my wife sat in the back and we discovered that putting a little tension on the seatbelt reduced it. So I went ahead and put the seatbelt in "car seat mode". If you don't know, most back seat seat belts can be put in a full ratcheting mode by pulling them all the way out. This is so you can tighten down a non-latch car seat without using clamps, etc. So I fastened the belt and ratched the belt tight against the seat. The rattle is gone!!!

So we now know the rattle is the passenger rear seatbelt mechanism.

The question:

Leave it like it is? We can make the rattle go away at will. Hopefully within a year baby #2 comes along and no one will ever sit there anyway for years (until the yet unborn baby outgrows a car seat at 3 to 4 years old).

Or

Have the dealer try to fix it? The risk is that things get worse: a new rattle or the rattle gets worse, etc. Or the trim pieces never quite go back on right, or a plastic gouge, etc.

What says AZ?

 

If it's not bothering you now, I'd leave it as it is for all the reasons you stated above.

 

agreed, leave it for now, have them check it out just before your bumper to bumper expires.