I emailed gmpartsdirect.com and got the below reply. I just ordered mine.

15686676 rear sear rear inner hinge (graphite), includes center and passenger's buckle.The part number you requested has been discontinued. GM hasa limited quantity of them left.[/align][/align]15686680 rear sear rear inner hinge (beige), includes center and passenger's buckle.The part number you requested has been discontinued and is no longer available from GM. You will have to find an aftermarket source for this part.[/align][/align]15686682 rear sear rear inner hinge (gray), includes center and passenger's buckle.The part number you requested has been discontinued and is no longer available from GM. You will have to find an aftermarket source for this part.[/align][/align]15966318 rear sear rear inner hinge (blue), includes center and passenger's buckle.The part number you requested has been discontinued and is no longer available from GM. You may be able to locate one through VPI (Vintage Parts Inc.) at 1 (877)846-8243.[/align]

 

If anyone has to do this it isn't necessary to replace the WHOLE hinge which is what the part numbers are for above. If you want you can replace just the buckle receiver part...although you cannot buy that new, it would have to be from a junk yard or used seat.

 

I shipped yours out thursday, it should be there sometime next week

 

Apparently my order at gmpartsdirect.com didnt go through, they wont ship but to the address on the credit card and I live in PO Box country and they wont ship to PO box so they cancelled my order. On to the next gm online parts store.