cegarbage, were you ever able to source a new buckle?
I may be in need of one myself for our 2003. Used is not an option I am particularly interested in for safety equipment if I can avoid it. I have a problem with not knowing what the stresses the components have endured previously (and whether they could withstand another round...)
Best I can tell is that the buckle changed part numbers starting in 2005, coinciding the Vibe's mid-cyle refresh that had a number of changes with the various restraint systems. The 2003-2004's are not showing available on the GM parts sites whereas the 2005-2008 do have it available (allegedly.) Not sure what changed over the years or whether they're compatible.
I checked a Toyota dealer's online parts catalog and they do show a part available for the 2003 Matrix XR. Starting in 2005, same as the Vibe, the Matrix's part number for the buckle changed and kept the new part number until the model end in 2008.
The buckle itself still works perfectly but for some reason the buckle assembly is flopping around loosely in all directions now (it still is bolted in and doesn't feel like it is going to come off.) I'm going to try to take the seat out and inspect as soon as I can, maybe remove/reinstall the buckle. Until then, the car will have to remain parked.
03 Vibe base. Born 10/14/2002 06:07 AM
Neptune. Auto, Moon & Tunes, power package. 129k mi.
'13 Sonic LT - 1.4L ECOTEC turbo/6A. 84k mi.
'15 Escape SE - 1.6L EcoBoost, FWD. 41k mi. (hers)